bromite/build/patches/experimental-user-scripts-support.patch

From: uazo <uazo@users.noreply.github.com>
Date: Sat, 20 Mar 2021 09:37:12 +0000
Subject: Experimental user scripts support preview
needs
add-support-for-ISupportHelpAndFeedback.patch
add-support-for-prefs-addon.patch

---
 chrome/android/BUILD.gn                       |   4 +
 .../chrome/browser/AfterStartupTaskUtils.java |   2 +
 .../browser/download/DownloadUtils.java       |   6 +
 chrome/android/java_sources.gni               |   3 +
 chrome/browser/BUILD.gn                       |   5 +
 chrome/browser/about_flags.cc                 |   9 +
 chrome/browser/flag_descriptions.cc           |  10 +
 chrome/browser/flag_descriptions.h            |   5 +
 chrome/browser/prefs/browser_prefs.cc         |   2 +
 ...hrome_browser_main_extra_parts_profiles.cc |   3 +
 chrome/browser/profiles/profile_manager.cc    |   9 +
 .../webui/chrome_web_ui_controller_factory.cc |   3 +
 chrome/chrome_paks.gni                        |   2 +
 chrome/renderer/BUILD.gn                      |   1 +
 .../chrome_content_renderer_client.cc         |  33 +
 components/components_strings.grd             |   1 +
 components/user_scripts/android/BUILD.gn      |  82 ++
 .../java/res/layout/accept_script_item.xml    |  74 ++
 .../java/res/layout/accept_script_list.xml    |  10 +
 .../java/res/layout/scripts_preference.xml    |  40 +
 .../android/java/res/values/dimens.xml        |  11 +
 .../main_preferences_addon_userscripts.xml    |  29 +
 .../java/res/xml/userscripts_preferences.xml  |  40 +
 .../user_scripts/UserScriptsUtils.java        |  78 ++
 .../user_scripts/FragmentWindowAndroid.java   |  68 ++
 .../user_scripts/IUserScriptsUtils.java       |  22 +
 .../components/user_scripts/ScriptInfo.java   |  33 +
 .../user_scripts/ScriptListBaseAdapter.java   | 194 +++++
 .../user_scripts/ScriptListPreference.java    | 169 ++++
 .../user_scripts/UserScriptsBridge.java       | 178 ++++
 .../user_scripts/UserScriptsPreferences.java  | 144 ++++
 .../user_scripts/android/java_sources.gni     |  18 +
 .../android/user_scripts_bridge.cc            | 179 ++++
 .../android/user_scripts_bridge.h             |  31 +
 components/user_scripts/browser/BUILD.gn      |  91 ++
 .../user_scripts/browser/file_task_runner.cc  |  40 +
 .../user_scripts/browser/file_task_runner.h   |  34 +
 .../browser/resources/browser_resources.grd   |  14 +
 .../browser/resources/user-script-ui/BUILD.gn |  12 +
 .../user-script-ui/user-scripts-ui.html       |  14 +
 .../user-script-ui/user-scripts-ui.js         |   9 +
 .../browser/ui/user_scripts_ui.cc             | 150 ++++
 .../user_scripts/browser/ui/user_scripts_ui.h |  39 +
 .../browser/user_script_loader.cc             | 657 ++++++++++++++
 .../user_scripts/browser/user_script_loader.h | 172 ++++
 .../browser/user_script_pref_info.cc          |  34 +
 .../browser/user_script_pref_info.h           |  66 ++
 .../user_scripts/browser/user_script_prefs.cc | 262 ++++++
 .../user_scripts/browser/user_script_prefs.h  |  58 ++
 .../browser/userscripts_browser_client.cc     |  79 ++
 .../browser/userscripts_browser_client.h      |  62 ++
 components/user_scripts/common/BUILD.gn       |  52 ++
 components/user_scripts/common/constants.h    |  21 +
 components/user_scripts/common/error_utils.cc |  54 ++
 components/user_scripts/common/error_utils.h  |  25 +
 .../common/extension_message_generator.cc     |  29 +
 .../common/extension_message_generator.h      |  11 +
 .../user_scripts/common/extension_messages.cc |  40 +
 .../user_scripts/common/extension_messages.h  |  70 ++
 components/user_scripts/common/host_id.cc     |  31 +
 components/user_scripts/common/host_id.h      |  35 +
 .../user_scripts/common/script_constants.h    |  33 +
 components/user_scripts/common/url_pattern.cc | 807 ++++++++++++++++++
 components/user_scripts/common/url_pattern.h  | 301 +++++++
 .../user_scripts/common/url_pattern_set.cc    | 330 +++++++
 .../user_scripts/common/url_pattern_set.h     | 161 ++++
 components/user_scripts/common/user_script.cc | 317 +++++++
 components/user_scripts/common/user_script.h  | 387 +++++++++
 .../common/user_scripts_features.cc           |  34 +
 .../common/user_scripts_features.h            |  35 +
 components/user_scripts/common/view_type.cc   |  39 +
 components/user_scripts/common/view_type.h    |  48 ++
 components/user_scripts/renderer/BUILD.gn     |  67 ++
 .../renderer/extension_frame_helper.cc        |  96 +++
 .../renderer/extension_frame_helper.h         |  92 ++
 .../user_scripts/renderer/injection_host.cc   |  12 +
 .../user_scripts/renderer/injection_host.h    |  42 +
 .../renderer/resources/greasemonkey_api.js    |  82 ++
 .../user_scripts_renderer_resources.grd       |  14 +
 .../user_scripts/renderer/script_context.cc   | 213 +++++
 .../user_scripts/renderer/script_context.h    |  70 ++
 .../user_scripts/renderer/script_injection.cc | 342 ++++++++
 .../user_scripts/renderer/script_injection.h  | 156 ++++
 .../renderer/script_injection_callback.cc     |  26 +
 .../renderer/script_injection_callback.h      |  38 +
 .../renderer/script_injection_manager.cc      | 417 +++++++++
 .../renderer/script_injection_manager.h       | 102 +++
 .../user_scripts/renderer/script_injector.h   |  96 +++
 .../user_scripts/renderer/scripts_run_info.cc |  31 +
 .../user_scripts/renderer/scripts_run_info.h  |  70 ++
 .../renderer/user_script_injector.cc          | 228 +++++
 .../renderer/user_script_injector.h           |  86 ++
 .../user_scripts/renderer/user_script_set.cc  | 258 ++++++
 .../user_scripts/renderer/user_script_set.h   | 102 +++
 .../renderer/user_script_set_manager.cc       |  77 ++
 .../renderer/user_script_set_manager.h        |  62 ++
 .../renderer/user_scripts_dispatcher.cc       |  36 +
 .../renderer/user_scripts_dispatcher.h        |  48 ++
 .../renderer/user_scripts_renderer_client.cc  |  76 ++
 .../renderer/user_scripts_renderer_client.h   |  33 +
 .../renderer/web_ui_injection_host.cc         |  40 +
 .../renderer/web_ui_injection_host.h          |  28 +
 .../strings/userscripts_strings.grdp          |  50 ++
 tools/gritsettings/resource_ids.spec          |   6 +
 104 files changed, 9247 insertions(+)
 create mode 100755 components/user_scripts/android/BUILD.gn
 create mode 100644 components/user_scripts/android/java/res/layout/accept_script_item.xml
 create mode 100644 components/user_scripts/android/java/res/layout/accept_script_list.xml
 create mode 100644 components/user_scripts/android/java/res/layout/scripts_preference.xml
 create mode 100755 components/user_scripts/android/java/res/values/dimens.xml
 create mode 100755 components/user_scripts/android/java/res/xml/main_preferences_addon_userscripts.xml
 create mode 100644 components/user_scripts/android/java/res/xml/userscripts_preferences.xml
 create mode 100755 components/user_scripts/android/java/src/org/chromium/chrome/browser/user_scripts/UserScriptsUtils.java
 create mode 100644 components/user_scripts/android/java/src/org/chromium/components/user_scripts/FragmentWindowAndroid.java
 create mode 100644 components/user_scripts/android/java/src/org/chromium/components/user_scripts/IUserScriptsUtils.java
 create mode 100644 components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptInfo.java
 create mode 100644 components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptListBaseAdapter.java
 create mode 100644 components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptListPreference.java
 create mode 100644 components/user_scripts/android/java/src/org/chromium/components/user_scripts/UserScriptsBridge.java
 create mode 100755 components/user_scripts/android/java/src/org/chromium/components/user_scripts/UserScriptsPreferences.java
 create mode 100644 components/user_scripts/android/java_sources.gni
 create mode 100644 components/user_scripts/android/user_scripts_bridge.cc
 create mode 100644 components/user_scripts/android/user_scripts_bridge.h
 create mode 100755 components/user_scripts/browser/BUILD.gn
 create mode 100755 components/user_scripts/browser/file_task_runner.cc
 create mode 100755 components/user_scripts/browser/file_task_runner.h
 create mode 100644 components/user_scripts/browser/resources/browser_resources.grd
 create mode 100644 components/user_scripts/browser/resources/user-script-ui/BUILD.gn
 create mode 100644 components/user_scripts/browser/resources/user-script-ui/user-scripts-ui.html
 create mode 100644 components/user_scripts/browser/resources/user-script-ui/user-scripts-ui.js
 create mode 100644 components/user_scripts/browser/ui/user_scripts_ui.cc
 create mode 100644 components/user_scripts/browser/ui/user_scripts_ui.h
 create mode 100755 components/user_scripts/browser/user_script_loader.cc
 create mode 100755 components/user_scripts/browser/user_script_loader.h
 create mode 100644 components/user_scripts/browser/user_script_pref_info.cc
 create mode 100644 components/user_scripts/browser/user_script_pref_info.h
 create mode 100644 components/user_scripts/browser/user_script_prefs.cc
 create mode 100644 components/user_scripts/browser/user_script_prefs.h
 create mode 100755 components/user_scripts/browser/userscripts_browser_client.cc
 create mode 100755 components/user_scripts/browser/userscripts_browser_client.h
 create mode 100755 components/user_scripts/common/BUILD.gn
 create mode 100755 components/user_scripts/common/constants.h
 create mode 100755 components/user_scripts/common/error_utils.cc
 create mode 100755 components/user_scripts/common/error_utils.h
 create mode 100755 components/user_scripts/common/extension_message_generator.cc
 create mode 100755 components/user_scripts/common/extension_message_generator.h
 create mode 100755 components/user_scripts/common/extension_messages.cc
 create mode 100755 components/user_scripts/common/extension_messages.h
 create mode 100755 components/user_scripts/common/host_id.cc
 create mode 100755 components/user_scripts/common/host_id.h
 create mode 100755 components/user_scripts/common/script_constants.h
 create mode 100755 components/user_scripts/common/url_pattern.cc
 create mode 100755 components/user_scripts/common/url_pattern.h
 create mode 100755 components/user_scripts/common/url_pattern_set.cc
 create mode 100755 components/user_scripts/common/url_pattern_set.h
 create mode 100755 components/user_scripts/common/user_script.cc
 create mode 100755 components/user_scripts/common/user_script.h
 create mode 100644 components/user_scripts/common/user_scripts_features.cc
 create mode 100644 components/user_scripts/common/user_scripts_features.h
 create mode 100755 components/user_scripts/common/view_type.cc
 create mode 100755 components/user_scripts/common/view_type.h
 create mode 100755 components/user_scripts/renderer/BUILD.gn
 create mode 100755 components/user_scripts/renderer/extension_frame_helper.cc
 create mode 100755 components/user_scripts/renderer/extension_frame_helper.h
 create mode 100755 components/user_scripts/renderer/injection_host.cc
 create mode 100755 components/user_scripts/renderer/injection_host.h
 create mode 100755 components/user_scripts/renderer/resources/greasemonkey_api.js
 create mode 100755 components/user_scripts/renderer/resources/user_scripts_renderer_resources.grd
 create mode 100755 components/user_scripts/renderer/script_context.cc
 create mode 100755 components/user_scripts/renderer/script_context.h
 create mode 100755 components/user_scripts/renderer/script_injection.cc
 create mode 100755 components/user_scripts/renderer/script_injection.h
 create mode 100755 components/user_scripts/renderer/script_injection_callback.cc
 create mode 100755 components/user_scripts/renderer/script_injection_callback.h
 create mode 100755 components/user_scripts/renderer/script_injection_manager.cc
 create mode 100755 components/user_scripts/renderer/script_injection_manager.h
 create mode 100755 components/user_scripts/renderer/script_injector.h
 create mode 100755 components/user_scripts/renderer/scripts_run_info.cc
 create mode 100755 components/user_scripts/renderer/scripts_run_info.h
 create mode 100755 components/user_scripts/renderer/user_script_injector.cc
 create mode 100755 components/user_scripts/renderer/user_script_injector.h
 create mode 100755 components/user_scripts/renderer/user_script_set.cc
 create mode 100755 components/user_scripts/renderer/user_script_set.h
 create mode 100755 components/user_scripts/renderer/user_script_set_manager.cc
 create mode 100755 components/user_scripts/renderer/user_script_set_manager.h
 create mode 100755 components/user_scripts/renderer/user_scripts_dispatcher.cc
 create mode 100755 components/user_scripts/renderer/user_scripts_dispatcher.h
 create mode 100755 components/user_scripts/renderer/user_scripts_renderer_client.cc
 create mode 100755 components/user_scripts/renderer/user_scripts_renderer_client.h
 create mode 100755 components/user_scripts/renderer/web_ui_injection_host.cc
 create mode 100755 components/user_scripts/renderer/web_ui_injection_host.h
 create mode 100755 components/user_scripts/strings/userscripts_strings.grdp

diff --git a/chrome/android/BUILD.gn b/chrome/android/BUILD.gn
--- a/chrome/android/BUILD.gn
+++ b/chrome/android/BUILD.gn
@@ -236,6 +236,9 @@ android_resources("chrome_app_java_resources") {
     "//third_party/androidx:androidx_preference_preference_java",
     "//third_party/androidx:androidx_recyclerview_recyclerview_java",
   ]
+
+  # insert into chrome_app_java_resources
+  deps += [ "//components/user_scripts/android:java_resources" ]
 }
 
 if (enable_vr) {
@@ -465,6 +468,7 @@ android_library("chrome_java") {
     "//components/translate/core/common:translate_infobar_event_enum_java",
     "//components/url_formatter/android:url_formatter_java",
     "//components/user_prefs/android:java",
+    "//components/user_scripts/android:java",
     "//components/variations/android:variations_java",
     "//components/version_info/android:version_constants_java",
     "//components/viz/common:common_java",
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/AfterStartupTaskUtils.java b/chrome/android/java/src/org/chromium/chrome/browser/AfterStartupTaskUtils.java
--- a/chrome/android/java/src/org/chromium/chrome/browser/AfterStartupTaskUtils.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/AfterStartupTaskUtils.java
@@ -4,6 +4,7 @@
 
 package org.chromium.chrome.browser;
 import org.chromium.base.annotations.NativeMethods;
+import org.chromium.chrome.browser.user_scripts.UserScriptsUtils;
 
 /**
  * JNI call glue for AfterStartupTaskUtils in C++.
@@ -17,6 +18,7 @@ public final class AfterStartupTaskUtils {
      * to run and newly posted tasks will no longer be deferred.
      */
     public static void setStartupComplete() {
+        UserScriptsUtils.Initialize();
         AfterStartupTaskUtilsJni.get().setStartupComplete();
     }
 
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java
--- a/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/DownloadUtils.java
@@ -62,6 +62,7 @@ import org.chromium.content_public.browser.BrowserStartupController;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.ui.base.DeviceFormFactor;
 import org.chromium.ui.widget.Toast;
+import org.chromium.chrome.browser.user_scripts.UserScriptsUtils;
 
 import java.io.File;
 
@@ -382,6 +383,11 @@ public class DownloadUtils {
         Context context = ContextUtils.getApplicationContext();
         DownloadManagerService service = DownloadManagerService.getDownloadManagerService();
 
+        if (UserScriptsUtils.getInstance().openFile(filePath, mimeType, downloadGuid,
+                            isOffTheRecord, originalUrl, referrer)) {
+            return true;
+        }
+
         // Check if Chrome should open the file itself.
         if (service.isDownloadOpenableInBrowser(isOffTheRecord, mimeType)) {
             // Share URIs use the content:// scheme when able, which looks bad when displayed
diff --git a/chrome/android/java_sources.gni b/chrome/android/java_sources.gni
--- a/chrome/android/java_sources.gni
+++ b/chrome/android/java_sources.gni
@@ -20,6 +20,7 @@ import("//components/feed/features.gni")
 import("//components/offline_pages/buildflags/features.gni")
 import("//components/omnibox/browser/test_java_sources.gni")
 import("//device/vr/buildflags/buildflags.gni")
+import("//components/user_scripts/android/java_sources.gni")
 
 chrome_java_sources += public_autofill_assistant_java_sources
 
@@ -53,3 +54,5 @@ if (enable_arcore) {
     "java/src/org/chromium/chrome/browser/vr/ArDelegateImpl.java",
   ]
 }
+
+chrome_java_sources += userscripts_java_sources
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -3377,6 +3377,11 @@ static_library("browser") {
       ]
       deps += [ "//chrome/android/modules/dev_ui/provider:native" ]
     }
+    deps += [
+      "//components/user_scripts/common",
+      "//components/user_scripts/browser",
+      "//components/user_scripts/android",
+    ]
   } else {
     #!is_android
     sources += [
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -138,6 +138,7 @@
 #include "components/translate/core/browser/translate_ranker_impl.h"
 #include "components/translate/core/common/translate_util.h"
 #include "components/ui_devtools/switches.h"
+#include "components/user_scripts/common/user_scripts_features.h"
 #include "components/version_info/version_info.h"
 #include "components/viz/common/features.h"
 #include "components/viz/common/switches.h"
@@ -6502,6 +6503,14 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(features::kUserDataSnapshot)},
 #endif
 
+    {"enable-userscripts", flag_descriptions::kEnableUserScriptsName,
+     flag_descriptions::kEnableUserScriptsDescription, kOsDesktop | kOsAndroid,
+     FEATURE_VALUE_TYPE(user_scripts::features::kEnableUserScripts)},
+
+    {"enable-userscripts-log", flag_descriptions::kEnableLoggingUserScriptsName,
+     flag_descriptions::kEnableLoggingUserScriptsDescription, kOsDesktop | kOsAndroid,
+     FEATURE_VALUE_TYPE(user_scripts::features::kEnableLoggingUserScripts)},
+
 #if defined(OS_WIN)
     {"run-video-capture-service-in-browser",
      flag_descriptions::kRunVideoCaptureServiceInBrowserProcessName,
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -5094,6 +5094,16 @@ const char kUserDataSnapshotDescription[] =
     "update and restoring them after a version rollback.";
 #endif  // !defined(OS_ANDROID) && !BUILDFLAG(IS_CHROMEOS_ASH)
 
+const char kEnableUserScriptsName[] = "Enable user scripts";
+const char kEnableUserScriptsDescription[] =
+    "Enables experimental support on user scripts. "
+    "Please report back any bug.";
+
+const char kEnableLoggingUserScriptsName[] = "Enable logging user scripts component";
+const char kEnableLoggingUserScriptsDescription[] =
+    "Enables logging for troubleshooting feature. "
+    "Please report back any bug.";
+
 #if defined(OS_WIN) || BUILDFLAG(IS_CHROMEOS_ASH) || defined(OS_MAC)
 const char kWebShareName[] = "Web Share";
 const char kWebShareDescription[] =
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -2995,6 +2995,11 @@ extern const char kUserDataSnapshotName[];
 extern const char kUserDataSnapshotDescription[];
 #endif  // !defined(OS_ANDROID) && !BUILDFLAG(IS_CHROMEOS_ASH)
 
+extern const char kEnableUserScriptsName[];
+extern const char kEnableUserScriptsDescription[];
+extern const char kEnableLoggingUserScriptsName[];
+extern const char kEnableLoggingUserScriptsDescription[];
+
 #if defined(OS_WIN) || BUILDFLAG(IS_CHROMEOS_ASH) || defined(OS_MAC)
 extern const char kWebShareName[];
 extern const char kWebShareDescription[];
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -227,6 +227,7 @@
 #include "components/ntp_tiles/popular_sites_impl.h"
 #include "components/permissions/contexts/geolocation_permission_context_android.h"
 #include "components/query_tiles/tile_service_prefs.h"
+#include "components/user_scripts/browser/user_script_prefs.h"
 #else  // defined(OS_ANDROID)
 #include "chrome/browser/accessibility/caption_controller.h"
 #include "chrome/browser/cart/cart_service.h"
@@ -969,6 +970,7 @@ void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry,
   translate::TranslatePrefs::RegisterProfilePrefs(registry);
   omnibox::RegisterProfilePrefs(registry);
   ZeroSuggestProvider::RegisterProfilePrefs(registry);
+  user_scripts::UserScriptsPrefs::RegisterProfilePrefs(registry);
 
 #if BUILDFLAG(ENABLE_SESSION_SERVICE)
   RegisterSessionServiceLogProfilePrefs(registry);
diff --git a/chrome/browser/profiles/chrome_browser_main_extra_parts_profiles.cc b/chrome/browser/profiles/chrome_browser_main_extra_parts_profiles.cc
--- a/chrome/browser/profiles/chrome_browser_main_extra_parts_profiles.cc
+++ b/chrome/browser/profiles/chrome_browser_main_extra_parts_profiles.cc
@@ -200,6 +200,8 @@
 #include "chrome/browser/lacros/cert_db_initializer_factory.h"
 #endif
 
+#include "components/user_scripts/browser/userscripts_browser_client.h"
+
 namespace chrome {
 
 void AddProfilesExtraParts(ChromeBrowserMainParts* main_parts) {
@@ -460,6 +462,7 @@ void ChromeBrowserMainExtraPartsProfiles::
 #endif
   WebDataServiceFactory::GetInstance();
   webrtc_event_logging::WebRtcEventLogManagerKeyedServiceFactory::GetInstance();
+  user_scripts::UserScriptsBrowserClient::GetInstance();
 }
 
 void ChromeBrowserMainExtraPartsProfiles::PreProfileInit() {
diff --git a/chrome/browser/profiles/profile_manager.cc b/chrome/browser/profiles/profile_manager.cc
--- a/chrome/browser/profiles/profile_manager.cc
+++ b/chrome/browser/profiles/profile_manager.cc
@@ -112,6 +112,8 @@
 #include "extensions/common/manifest.h"
 #endif
 
+#include "components/user_scripts/browser/userscripts_browser_client.h"
+
 #if BUILDFLAG(ENABLE_SESSION_SERVICE)
 #include "chrome/browser/sessions/session_service_factory.h"
 #endif
@@ -1465,6 +1467,13 @@ void ProfileManager::DoFinalInitForServices(Profile* profile,
   }
 
 #endif
+
+  user_scripts::UserScriptsBrowserClient* userscript_client =
+    user_scripts::UserScriptsBrowserClient::GetInstance();
+  if(userscript_client) {
+    userscript_client->SetProfile(profile);
+  }
+
 #if BUILDFLAG(ENABLE_SUPERVISED_USERS)
   // Initialization needs to happen after extension system initialization (for
   // extension::ManagementPolicy) and InitProfileUserPrefs (for setting the
diff --git a/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc b/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
--- a/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
+++ b/chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc
@@ -84,6 +84,7 @@
 #include "components/security_interstitials/content/urls.h"
 #include "components/signin/public/base/signin_buildflags.h"
 #include "components/site_engagement/content/site_engagement_service.h"
+#include "components/user_scripts/browser/ui/user_scripts_ui.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/common/content_client.h"
@@ -588,6 +589,8 @@ WebUIFactoryFunction GetWebUIFactoryFunction(WebUI* web_ui,
     return &NewWebUI<UserActionsUI>;
   if (url.host_piece() == chrome::kChromeUIVersionHost)
     return &NewWebUI<VersionUI>;
+  if (url.host_piece() == user_scripts::kChromeUIUserScriptsHost)
+    return &NewWebUI<user_scripts::UserScriptsUI>;
 
 #if !defined(OS_ANDROID)
 #if !BUILDFLAG(IS_CHROMEOS_ASH)
diff --git a/chrome/chrome_paks.gni b/chrome/chrome_paks.gni
--- a/chrome/chrome_paks.gni
+++ b/chrome/chrome_paks.gni
@@ -104,6 +104,7 @@ template("chrome_extra_paks") {
       "$root_gen_dir/third_party/blink/public/resources/inspector_overlay_resources.pak",
       "$root_gen_dir/ui/resources/webui_generated_resources.pak",
       "$root_gen_dir/ui/resources/webui_resources.pak",
+      "$root_gen_dir/chrome/userscripts_browser_resources.pak",
     ]
     deps = [
       "//base/tracing/protos:chrome_track_event_resources",
@@ -119,6 +120,7 @@ template("chrome_extra_paks") {
       "//third_party/blink/public:devtools_inspector_resources",
       "//third_party/blink/public:resources",
       "//ui/resources",
+      "//components/user_scripts/browser:userscripts_browser_resources_grit",
     ]
     if (defined(invoker.deps)) {
       deps += invoker.deps
diff --git a/chrome/renderer/BUILD.gn b/chrome/renderer/BUILD.gn
--- a/chrome/renderer/BUILD.gn
+++ b/chrome/renderer/BUILD.gn
@@ -163,6 +163,7 @@ static_library("renderer") {
     "//components/contextual_search/content:renderer",
     "//components/data_reduction_proxy/core/common",
     "//components/dom_distiller/content/renderer",
+    "//components/user_scripts/renderer",
     "//components/network_hints/renderer",
     "//components/no_state_prefetch/common",
     "//components/no_state_prefetch/renderer",
diff --git a/chrome/renderer/chrome_content_renderer_client.cc b/chrome/renderer/chrome_content_renderer_client.cc
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -168,6 +168,8 @@
 #include "chrome/renderer/sandbox_status_extension_android.h"
 #include "components/continuous_search/renderer/search_result_extractor_impl.h"  // nogncheck
 #include "components/embedder_support/android/common/url_constants.h"
+#include "components/user_scripts/common/user_scripts_features.h"
+#include "components/user_scripts/renderer/user_scripts_renderer_client.h"
 #else
 #include "chrome/renderer/cart/commerce_hint_agent.h"
 #include "chrome/renderer/media/chrome_speech_recognition_client.h"
@@ -363,6 +365,12 @@ void ChromeContentRendererClient::RenderThreadStarted() {
   ChromeExtensionsRendererClient::GetInstance()->RenderThreadStarted();
 #endif
 
+  user_scripts::UserScriptsRendererClient* userscript_client =
+    user_scripts::UserScriptsRendererClient::GetInstance();
+  if(userscript_client) {
+    userscript_client->RenderThreadStarted();
+  }
+
 #if BUILDFLAG(ENABLE_SPELLCHECK)
   if (!spellcheck_)
     InitSpellCheck();
@@ -493,6 +501,13 @@ void ChromeContentRendererClient::RenderFrameCreated(
       render_frame, registry);
 #endif
 
+  user_scripts::UserScriptsRendererClient* userscript_client =
+    user_scripts::UserScriptsRendererClient::GetInstance();
+  if(userscript_client) {
+    userscript_client->RenderFrameCreated(
+      render_frame, registry);
+  }
+
 #if BUILDFLAG(ENABLE_PLUGINS)
   new PepperHelper(render_frame);
 #endif
@@ -1455,6 +1470,12 @@ void ChromeContentRendererClient::RunScriptsAtDocumentStart(
       render_frame);
   // |render_frame| might be dead by now.
 #endif
+  user_scripts::UserScriptsRendererClient* userscript_client =
+    user_scripts::UserScriptsRendererClient::GetInstance();
+  if(userscript_client) {
+    userscript_client->RunScriptsAtDocumentStart(
+      render_frame);
+  }
 }
 
 void ChromeContentRendererClient::RunScriptsAtDocumentEnd(
@@ -1464,6 +1485,12 @@ void ChromeContentRendererClient::RunScriptsAtDocumentEnd(
       render_frame);
   // |render_frame| might be dead by now.
 #endif
+  user_scripts::UserScriptsRendererClient* userscript_client =
+    user_scripts::UserScriptsRendererClient::GetInstance();
+  if(userscript_client) {
+    userscript_client->RunScriptsAtDocumentEnd(
+      render_frame);
+  }
 }
 
 void ChromeContentRendererClient::RunScriptsAtDocumentIdle(
@@ -1473,6 +1500,12 @@ void ChromeContentRendererClient::RunScriptsAtDocumentIdle(
       render_frame);
   // |render_frame| might be dead by now.
 #endif
+  user_scripts::UserScriptsRendererClient* userscript_client =
+    user_scripts::UserScriptsRendererClient::GetInstance();
+  if(userscript_client) {
+    userscript_client->RunScriptsAtDocumentIdle(
+      render_frame);
+  }
 }
 
 void ChromeContentRendererClient::
diff --git a/components/components_strings.grd b/components/components_strings.grd
--- a/components/components_strings.grd
+++ b/components/components_strings.grd
@@ -327,6 +327,7 @@
       <part file="undo_strings.grdp" />
       <part file="version_ui_strings.grdp" />
       <part file="webapps_strings.grdp" />
+      <part file="user_scripts/strings/userscripts_strings.grdp" />
 
       <if expr="not is_android and not is_ios">
         <part file="management_strings.grdp" />
diff --git a/components/user_scripts/android/BUILD.gn b/components/user_scripts/android/BUILD.gn
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/android/BUILD.gn
@@ -0,0 +1,82 @@
+# This file is part of Bromite.
+
+# Bromite is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# Bromite is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+
+import("//build/config/android/rules.gni")
+
+generate_jni("user_scripts_jni_headers") {
+  sources = [ "java/src/org/chromium/components/user_scripts/UserScriptsBridge.java" ]
+}
+
+android_resources("java_resources") {
+  sources = [
+    "java/res/xml/main_preferences_addon_userscripts.xml",
+    "java/res/xml/userscripts_preferences.xml",
+    "java/res/layout/accept_script_item.xml",
+    "java/res/layout/accept_script_list.xml",
+    "java/res/layout/scripts_preference.xml",
+    "java/res/values/dimens.xml"
+   ]
+
+  deps = [
+    "//components/browser_ui/strings/android:browser_ui_strings_grd",
+    "//components/browser_ui/styles/android:java_resources",
+    "//components/strings:components_strings_grd",
+    "//ui/android:ui_java_resources",
+  ]
+}
+
+android_library("java") {
+  sources = [
+    "java/src/org/chromium/components/user_scripts/FragmentWindowAndroid.java",
+    "java/src/org/chromium/components/user_scripts/UserScriptsPreferences.java",
+    "java/src/org/chromium/components/user_scripts/UserScriptsBridge.java",
+    "java/src/org/chromium/components/user_scripts/IUserScriptsUtils.java",
+    "java/src/org/chromium/components/user_scripts/ScriptListBaseAdapter.java",
+    "java/src/org/chromium/components/user_scripts/ScriptListPreference.java",
+    "java/src/org/chromium/components/user_scripts/ScriptInfo.java",
+  ]
+  deps = [
+    ":java_resources",
+    "//base:base_java",
+    "//base:jni_java",
+    "//components/embedder_support/android:browser_context_java",
+    "//components/browser_ui/settings/android:java",
+    "//components/browser_ui/widget/android:java",
+    "//content/public/android:content_java",
+    "//components/prefs/android:java",
+    "//third_party/android_deps:android_support_v7_appcompat_java",
+    "//third_party/androidx:androidx_annotation_annotation_java",
+    "//third_party/androidx:androidx_appcompat_appcompat_resources_java",
+    "//third_party/androidx:androidx_preference_preference_java",
+    "//ui/android:ui_java",
+  ]
+  resources_package = "org.chromium.components.user_scripts"
+  annotation_processor_deps = [ "//base/android/jni_generator:jni_processor" ]
+}
+
+source_set("android") {
+  sources = [
+    "user_scripts_bridge.cc",
+    "user_scripts_bridge.h",
+  ]
+  deps = [
+    ":user_scripts_jni_headers",
+    "//base",
+    "//components/user_scripts/browser",
+    "//components/embedder_support/android:browser_context",
+    "//components/permissions",
+    "//content/public/browser",
+  ]
+}
diff --git a/components/user_scripts/android/java/res/layout/accept_script_item.xml b/components/user_scripts/android/java/res/layout/accept_script_item.xml
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/res/layout/accept_script_item.xml
@@ -0,0 +1,74 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2017 The Chromium Authors. All rights reserved.
+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file. -->
+
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/language_item"
+    android:layout_marginStart="0dp"
+    android:paddingStart="@dimen/draggable_list_item_padding"
+    android:paddingEnd="@dimen/draggable_list_item_padding"
+    style="@style/ListItemContainer">
+
+    <Switch
+        android:id="@+id/switch_widget"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:paddingEnd="15dp"
+        android:focusable="false"
+        android:background="@null" />
+
+    <LinearLayout
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_weight="1"
+        android:orientation="vertical"
+        android:layout_gravity="center_vertical" >
+
+        <TextView
+            android:id="@+id/title"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            style="@style/PreferenceTitle" />
+
+        <TextView
+            android:id="@+id/description"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            style="@style/PreferenceSummary" />
+
+        <TextView
+            android:id="@+id/version"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            style="@style/PreferenceSummary" />
+
+        <TextView
+            android:id="@+id/file"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            style="@style/PreferenceSummary" />
+
+        <TextView
+            android:id="@+id/url"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            style="@style/PreferenceSummary" />
+
+    </LinearLayout>
+
+    <org.chromium.components.browser_ui.widget.listmenu.ListMenuButton
+        android:id="@+id/more"
+        android:layout_width="wrap_content"
+        android:layout_height="match_parent"
+        android:paddingStart="@dimen/default_list_row_padding"
+        android:paddingEnd="@dimen/default_list_row_padding"
+        android:background="@null"
+        android:src="@drawable/ic_more_vert_24dp"
+        app:menuMaxWidth="@dimen/pref_scripts_item_popup_width"
+        app:tint="@color/default_icon_color_tint_list"
+        tools:ignore="ContentDescription" />
+</LinearLayout>
\ No newline at end of file
diff --git a/components/user_scripts/android/java/res/layout/accept_script_list.xml b/components/user_scripts/android/java/res/layout/accept_script_list.xml
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/res/layout/accept_script_list.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2017 The Chromium Authors. All rights reserved.
+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file. -->
+
+<androidx.recyclerview.widget.RecyclerView
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/script_list"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content" />
\ No newline at end of file
diff --git a/components/user_scripts/android/java/res/layout/scripts_preference.xml b/components/user_scripts/android/java/res/layout/scripts_preference.xml
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/res/layout/scripts_preference.xml
@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2017 The Chromium Authors. All rights reserved.
+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file. -->
+
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:id="@+id/accept_scripts_list_container"
+    style="@style/PreferenceLayout"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:paddingStart="0dp"
+    android:paddingEnd="0dp"
+    android:padding="0dp"
+    android:orientation="vertical" >
+
+    <TextView
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:padding="@dimen/draggable_list_item_padding"
+        android:text="@string/scripts_list_description" />
+
+    <FrameLayout
+        android:id="@android:id/widget_frame"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content" />
+
+    <TextView
+        android:id="@+id/add_script"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:background="?attr/selectableItemBackground"
+        android:clickable="true"
+        android:gravity="center_vertical"
+        android:padding="@dimen/draggable_list_item_padding"
+        android:paddingStart="@dimen/pref_scripts_add_button_padding"
+        android:drawablePadding="@dimen/pref_scripts_add_button_padding"
+        android:text="@string/add_script"
+        style="@style/PreferenceTitle" />
+
+</LinearLayout>
\ No newline at end of file
diff --git a/components/user_scripts/android/java/res/values/dimens.xml b/components/user_scripts/android/java/res/values/dimens.xml
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/android/java/res/values/dimens.xml
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright 2014 The Chromium Authors. All rights reserved.
+     Use of this source code is governed by a BSD-style license that can be
+     found in the LICENSE file. -->
+
+<resources xmlns:tools="http://schemas.android.com/tools">
+
+    <dimen name="pref_scripts_add_button_padding">24dp</dimen>
+    <dimen name="pref_scripts_item_popup_width">260dp</dimen>
+
+</resources>
diff --git a/components/user_scripts/android/java/res/xml/main_preferences_addon_userscripts.xml b/components/user_scripts/android/java/res/xml/main_preferences_addon_userscripts.xml
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/android/java/res/xml/main_preferences_addon_userscripts.xml
@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+-->
+
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:orderingFromXml="false">
+
+    <Preference
+        android:fragment="org.chromium.components.user_scripts.UserScriptsPreferences"
+        android:key="userscripts_settings"
+        android:order="20"
+        android:title="@string/prefs_userscripts_settings"/>
+
+</PreferenceScreen>
diff --git a/components/user_scripts/android/java/res/xml/userscripts_preferences.xml b/components/user_scripts/android/java/res/xml/userscripts_preferences.xml
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/res/xml/userscripts_preferences.xml
@@ -0,0 +1,40 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+-->
+
+<PreferenceScreen
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <org.chromium.components.browser_ui.settings.TextMessagePreference
+        android:key="scripts_disabled_description"
+        android:title="@string/scripts_disabled_description"
+        app:allowDividerBelow="false"
+        app:isPreferenceVisible="false"/>
+
+    <org.chromium.components.browser_ui.settings.ChromeSwitchPreference
+        android:key="enabled_switch"
+        android:title="@string/option_userscript_flag"
+        android:summaryOn="@string/option_userscript_flag_on"
+        android:summaryOff="@string/option_userscript_flag_off" />
+
+    <org.chromium.components.user_scripts.ScriptListPreference
+        android:key="script_list"
+        android:layout="@layout/scripts_preference"
+        android:widgetLayout="@layout/accept_script_list" />
+
+</PreferenceScreen>
diff --git a/components/user_scripts/android/java/src/org/chromium/chrome/browser/user_scripts/UserScriptsUtils.java b/components/user_scripts/android/java/src/org/chromium/chrome/browser/user_scripts/UserScriptsUtils.java
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/android/java/src/org/chromium/chrome/browser/user_scripts/UserScriptsUtils.java
@@ -0,0 +1,78 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package org.chromium.chrome.browser.user_scripts;
+
+import android.content.Context;
+import android.content.Intent;
+import android.provider.Browser;
+import android.net.Uri;
+
+import org.chromium.base.ContextUtils;
+import org.chromium.base.IntentUtils;
+
+import org.chromium.chrome.browser.IntentHandler;
+import org.chromium.chrome.browser.settings.SettingsLauncherImpl;
+import org.chromium.components.browser_ui.settings.SettingsLauncher;
+
+import org.chromium.components.user_scripts.UserScriptsPreferences;
+import org.chromium.components.user_scripts.UserScriptsBridge;
+import org.chromium.components.user_scripts.IUserScriptsUtils;
+
+public class UserScriptsUtils implements IUserScriptsUtils
+{
+    private static UserScriptsUtils instance;
+
+    private UserScriptsUtils() {}
+
+    public static void Initialize() {
+        instance = new UserScriptsUtils();
+        UserScriptsBridge.registerUtils(instance);
+    }
+
+    public static UserScriptsUtils getInstance() {
+        return instance;
+    }
+
+    public boolean openFile(String filePath, String mimeType, String downloadGuid,
+                                   boolean isOffTheRecord, String originalUrl, String referrer) {
+        if (UserScriptsBridge.isUserEnabled() == false) return false;
+
+        if (filePath.toUpperCase().endsWith(".USER.JS") == false) return false;
+
+        Context context = ContextUtils.getApplicationContext();
+
+        SettingsLauncher settingsLauncher = new SettingsLauncherImpl();
+        Intent intent = settingsLauncher.createSettingsActivityIntent(
+                context, UserScriptsPreferences.class.getName(),
+                UserScriptsPreferences.createFragmentArgsForInstall(filePath));
+        IntentUtils.safeStartActivity(context, intent);
+
+        return true;
+    }
+
+    public void openSourceFile(String scriptKey) {
+        Context context = ContextUtils.getApplicationContext();
+
+        Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("chrome://user-scripts/?key=" + scriptKey));
+        intent.putExtra(Browser.EXTRA_APPLICATION_ID, context.getPackageName());
+        intent.putExtra(Browser.EXTRA_CREATE_NEW_TAB, true);
+        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        intent.setPackage(context.getPackageName());
+        IntentHandler.startChromeLauncherActivityForTrustedIntent(intent);
+    }
+}
\ No newline at end of file
diff --git a/components/user_scripts/android/java/src/org/chromium/components/user_scripts/FragmentWindowAndroid.java b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/FragmentWindowAndroid.java
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/FragmentWindowAndroid.java
@@ -0,0 +1,68 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.components.user_scripts;
+
+import android.annotation.TargetApi;
+import android.app.Activity;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentSender;
+import android.os.Build;
+import android.view.View;
+
+import androidx.fragment.app.Fragment;
+
+import org.chromium.ui.base.ActivityKeyboardVisibilityDelegate;
+import org.chromium.ui.base.ActivityAndroidPermissionDelegate;
+import org.chromium.ui.base.ImmutableWeakReference;
+import org.chromium.ui.base.IntentWindowAndroid;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * Implements intent sending for a fragment based window. This should be created when
+ * onAttach() is called on the fragment, and destroyed when onDetach() is called.
+ */
+public class FragmentWindowAndroid extends IntentWindowAndroid {
+    private Fragment mFragment;
+
+    // This WeakReference is purely to avoid gc churn of creating a new WeakReference in
+    // every getActivity call. It is not needed for correctness.
+    private ImmutableWeakReference<Activity> mActivityWeakRefHolder;
+
+    FragmentWindowAndroid(Context context, Fragment fragment) {
+        super(context);
+        mFragment = fragment;
+
+        setKeyboardDelegate(new ActivityKeyboardVisibilityDelegate(getActivity()));
+        setAndroidPermissionDelegate(new ActivityAndroidPermissionDelegate(getActivity()));
+    }
+
+    @Override
+    protected final boolean startIntentSenderForResult(IntentSender intentSender, int requestCode) {
+        try {
+            mFragment.startIntentSenderForResult(
+                    intentSender, requestCode, new Intent(), 0, 0, 0, null);
+        } catch (IntentSender.SendIntentException e) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    protected final boolean startActivityForResult(Intent intent, int requestCode) {
+        mFragment.startActivityForResult(intent, requestCode, null);
+        return true;
+    }
+
+    @Override
+    public final WeakReference<Activity> getActivity() {
+        if (mActivityWeakRefHolder == null
+                || mActivityWeakRefHolder.get() != mFragment.getActivity()) {
+            mActivityWeakRefHolder = new ImmutableWeakReference<>(mFragment.getActivity());
+        }
+        return mActivityWeakRefHolder;
+    }
+}
\ No newline at end of file
diff --git a/components/user_scripts/android/java/src/org/chromium/components/user_scripts/IUserScriptsUtils.java b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/IUserScriptsUtils.java
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/IUserScriptsUtils.java
@@ -0,0 +1,22 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package org.chromium.components.user_scripts;
+
+public interface IUserScriptsUtils {
+    public void openSourceFile(String scriptKey);
+}
\ No newline at end of file
diff --git a/components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptInfo.java b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptInfo.java
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptInfo.java
@@ -0,0 +1,33 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package org.chromium.components.user_scripts;
+
+import java.time.LocalDateTime;
+
+public class ScriptInfo {
+    public String Key;
+    public String Name;
+    public String Description;
+    public String Version;
+    public String FilePath;
+    public String UrlSource;
+    public boolean Enabled;
+    public LocalDateTime InstallTime;
+
+    public ScriptInfo() {}
+}
diff --git a/components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptListBaseAdapter.java b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptListBaseAdapter.java
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptListBaseAdapter.java
@@ -0,0 +1,194 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package org.chromium.components.user_scripts;
+
+import android.content.Context;
+import android.view.LayoutInflater;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.accessibility.AccessibilityManager;
+import android.view.accessibility.AccessibilityManager.AccessibilityStateChangeListener;
+import android.widget.ImageView;
+import android.widget.TextView;
+import android.widget.Switch;
+import android.widget.CompoundButton;
+
+import androidx.annotation.DrawableRes;
+import androidx.annotation.NonNull;
+import androidx.core.view.ViewCompat;
+import androidx.recyclerview.widget.RecyclerView.ViewHolder;
+
+import org.chromium.components.browser_ui.widget.dragreorder.DragReorderableListAdapter;
+import org.chromium.components.browser_ui.widget.dragreorder.DragStateDelegate;
+import org.chromium.components.browser_ui.widget.listmenu.ListMenuButton;
+import org.chromium.components.browser_ui.widget.listmenu.ListMenuButtonDelegate;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ScriptListBaseAdapter extends DragReorderableListAdapter<ScriptInfo> {
+
+    class ItemClickListener {
+        void onScriptOnOff(boolean Enabled) {}
+        void onScriptClicked() {}
+    }
+
+    static class ScriptInfoRowViewHolder extends ViewHolder {
+        private TextView mTitle;
+        private TextView mDescription;
+        private TextView mVersion;
+        private TextView mFile;
+        private TextView mUrl;
+        private Switch mSwitch;
+
+        private ListMenuButton mMoreButton;
+
+        private CompoundButton.OnCheckedChangeListener mOnOffListener;
+
+        ScriptInfoRowViewHolder(View view) {
+            super(view);
+
+            mSwitch = view.findViewById(R.id.switch_widget);
+            mTitle = view.findViewById(R.id.title);
+            mDescription = view.findViewById(R.id.description);
+            mVersion = view.findViewById(R.id.version);
+            mFile = view.findViewById(R.id.file);
+            mUrl = view.findViewById(R.id.url);
+
+            mMoreButton = view.findViewById(R.id.more);
+        }
+
+        protected void updateScriptInfo(ScriptInfo item) {
+            mSwitch.setOnCheckedChangeListener(null);
+            mSwitch.setChecked(item.Enabled);
+            mSwitch.setOnCheckedChangeListener(mOnOffListener);
+
+            mTitle.setText(item.Name);
+            mDescription.setText(item.Description);
+            mVersion.setText(item.Version);
+            mFile.setText(item.Key);
+            mUrl.setText(item.UrlSource);
+
+            if (item.UrlSource == null || item.UrlSource.isEmpty()) {
+                mUrl.setVisibility(View.GONE);
+            }
+        }
+
+        void setMenuButtonDelegate(@NonNull ListMenuButtonDelegate delegate) {
+            mMoreButton.setVisibility(View.VISIBLE);
+            mMoreButton.setDelegate(delegate);
+            // Set item row end padding 0 when MenuButton is visible.
+            ViewCompat.setPaddingRelative(itemView, ViewCompat.getPaddingStart(itemView),
+                    itemView.getPaddingTop(), 0, itemView.getPaddingBottom());
+        }
+
+        void setItemListener(@NonNull ItemClickListener listener) {
+            mOnOffListener = (buttonView, isChecked) -> listener.onScriptOnOff(isChecked);
+            mSwitch.setOnCheckedChangeListener(mOnOffListener);
+            itemView.setOnClickListener(view -> listener.onScriptClicked());
+        }
+    }
+
+    private class ScriptDragStateDelegate implements DragStateDelegate {
+        private AccessibilityManager mA11yManager;
+        private AccessibilityStateChangeListener mA11yListener;
+        private boolean mA11yEnabled;
+
+        public ScriptDragStateDelegate() {
+            mA11yManager =
+                    (AccessibilityManager) mContext.getSystemService(Context.ACCESSIBILITY_SERVICE);
+            mA11yEnabled = mA11yManager.isEnabled();
+            mA11yListener = enabled -> {
+                mA11yEnabled = enabled;
+                notifyDataSetChanged();
+            };
+            mA11yManager.addAccessibilityStateChangeListener(mA11yListener);
+        }
+
+        @Override
+        public boolean getDragEnabled() {
+            return !mA11yEnabled;
+        }
+
+        @Override
+        public boolean getDragActive() {
+            return getDragEnabled();
+        }
+
+        @Override
+        public void setA11yStateForTesting(boolean a11yEnabled) {
+        }
+    }
+
+    ScriptListBaseAdapter(Context context) {
+        super(context);
+        setDragStateDelegate(new ScriptDragStateDelegate());
+    }
+
+    void showDragIndicatorInRow(ScriptInfoRowViewHolder holder) {
+        // Quit if it's not applicable.
+        if (getItemCount() <= 1 || !mDragStateDelegate.getDragEnabled()) return;
+
+        // assert mItemTouchHelper != null;
+        // //holder.setStartIcon(R.drawable.ic_drag_handle_grey600_24dp);
+        // holder.mStartIcon.setOnTouchListener((v, event) -> {
+        //     if (event.getActionMasked() == MotionEvent.ACTION_DOWN) {
+        //         mItemTouchHelper.startDrag(holder);
+        //     }
+        //     return false;
+        // });
+    }
+
+    @Override
+    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
+        View row = LayoutInflater.from(viewGroup.getContext())
+                           .inflate(R.layout.accept_script_item, viewGroup, false);
+        return new ScriptInfoRowViewHolder(row);
+    }
+
+    @Override
+    public void onBindViewHolder(ViewHolder viewHolder, int i) {
+        ((ScriptInfoRowViewHolder) viewHolder).updateScriptInfo(mElements.get(i));
+    }
+
+    @Override
+    protected void setOrder(List<ScriptInfo> order) {
+        // String[] codes = new String[order.size()];
+        // for (int i = 0; i < order.size(); i++) {
+        //     codes[i] = order.get(i).getCode();
+        // }
+        //LanguagesManager.getInstance().setOrder(codes, false);
+        //notifyDataSetChanged();
+    }
+
+    void setDisplayedScriptInfo(List<ScriptInfo> values) {
+        mElements = new ArrayList<>(values);
+        notifyDataSetChanged();
+    }
+
+    @Override
+    protected boolean isActivelyDraggable(ViewHolder viewHolder) {
+        return isPassivelyDraggable(viewHolder);
+    }
+
+    @Override
+    protected boolean isPassivelyDraggable(ViewHolder viewHolder) {
+        return viewHolder instanceof ScriptInfoRowViewHolder;
+    }
+}
diff --git a/components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptListPreference.java b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptListPreference.java
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/ScriptListPreference.java
@@ -0,0 +1,169 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package org.chromium.components.user_scripts;
+
+import static org.chromium.components.browser_ui.widget.listmenu.BasicListMenu.buildMenuListItem;
+import static org.chromium.components.browser_ui.widget.listmenu.BasicListMenu.buildMenuListItemWithEndIcon;
+
+import android.content.Context;
+import android.content.Intent;
+import android.provider.Browser;
+import android.net.Uri;
+import android.util.AttributeSet;
+import android.widget.TextView;
+import android.widget.Toast;
+
+import androidx.preference.Preference;
+import androidx.preference.PreferenceViewHolder;
+import androidx.recyclerview.widget.DividerItemDecoration;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+import androidx.recyclerview.widget.RecyclerView.ViewHolder;
+
+import org.chromium.ui.base.WindowAndroid;
+import org.chromium.ui.base.ActivityWindowAndroid;
+
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.ContextUtils;
+import org.chromium.components.browser_ui.widget.TintedDrawable;
+import org.chromium.components.browser_ui.widget.listmenu.BasicListMenu;
+import org.chromium.components.browser_ui.widget.listmenu.ListMenu;
+import org.chromium.components.browser_ui.widget.listmenu.ListMenuItemProperties;
+import org.chromium.ui.modelutil.MVCListAdapter.ModelList;
+
+import org.chromium.components.user_scripts.ScriptListBaseAdapter;
+import org.chromium.components.user_scripts.FragmentWindowAndroid;
+
+public class ScriptListPreference extends Preference {
+    private static class ScriptListAdapter
+            extends ScriptListBaseAdapter {
+        private final Context mContext;
+
+        ScriptListAdapter(Context context) {
+            super(context);
+            mContext = context;
+        }
+
+        @Override
+        public void onBindViewHolder(ViewHolder holder, int position) {
+            super.onBindViewHolder(holder, position);
+
+            final ScriptInfo info = getItemByPosition(position);
+
+            showDragIndicatorInRow((ScriptInfoRowViewHolder) holder);
+            ModelList menuItems = new ModelList();
+
+            menuItems.add(buildMenuListItem(R.string.remove, 0, 0, true));
+            menuItems.add(buildMenuListItem(R.string.scripts_open_url, 0, 0, info.UrlSource != null &&
+                                                                        info.UrlSource.isEmpty() == false));
+            menuItems.add(buildMenuListItem(R.string.scripts_view_source, 0, 0, true));
+
+            ListMenu.Delegate delegate = (model) -> {
+                int textId = model.get(ListMenuItemProperties.TITLE_ID);
+                if (textId == R.string.remove) {
+                    UserScriptsBridge.RemoveScript(info.Key);
+                } else if (textId == R.string.scripts_view_source) {
+                    UserScriptsBridge.getUtils().openSourceFile(info.Key);
+                } else if (textId == R.string.scripts_open_url) {
+                    Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(info.UrlSource));
+                    intent.putExtra(Browser.EXTRA_APPLICATION_ID, mContext.getPackageName());
+                    intent.putExtra(Browser.EXTRA_CREATE_NEW_TAB, true);
+                    intent.setPackage(mContext.getPackageName());
+                    mContext.startActivity(intent);
+                }
+            };
+            ((ScriptInfoRowViewHolder) holder)
+                    .setMenuButtonDelegate(() -> new BasicListMenu(mContext, menuItems, delegate));
+            ((ScriptInfoRowViewHolder) holder)
+                    .setItemListener(new ScriptListBaseAdapter.ItemClickListener() {
+                        @Override
+                        public void onScriptOnOff(boolean Enabled) {
+                            UserScriptsBridge.SetScriptEnabled(info.Key, Enabled);
+                        }
+
+                        @Override
+                        public void onScriptClicked() {}
+                    });
+        }
+
+        // @Override
+        public void onDataUpdated() {
+            if (mDragStateDelegate.getDragActive()) {
+                enableDrag();
+            } else {
+                disableDrag();
+            }
+            setDisplayedScriptInfo(UserScriptsBridge.getUserScriptItems());
+        }
+    }
+
+    private TextView mAddButton;
+    private RecyclerView mRecyclerView;
+    private ScriptListAdapter mAdapter;
+    private FragmentWindowAndroid mWindowAndroid;
+
+    public ScriptListPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        mAdapter = new ScriptListAdapter(context);
+    }
+
+    public void setWindowAndroid(FragmentWindowAndroid windowAndroid) {
+        mWindowAndroid = windowAndroid;
+    }
+
+    @Override
+    public void onBindViewHolder(PreferenceViewHolder holder) {
+        super.onBindViewHolder(holder);
+
+        mAddButton = (TextView) holder.findViewById(R.id.add_script);
+        mAddButton.setCompoundDrawablesRelativeWithIntrinsicBounds(
+                TintedDrawable.constructTintedDrawable(
+                        getContext(), R.drawable.plus, R.color.default_control_color_active),
+                null, null, null);
+        mAddButton.setOnClickListener(view -> {
+            UserScriptsBridge.SelectAndAddScriptFromFile(mWindowAndroid);
+        });
+
+        mRecyclerView = (RecyclerView) holder.findViewById(R.id.script_list);
+        LinearLayoutManager layoutManager = new LinearLayoutManager(getContext());
+        mRecyclerView.setLayoutManager(layoutManager);
+        mRecyclerView.addItemDecoration(
+                new DividerItemDecoration(getContext(), layoutManager.getOrientation()));
+
+        UserScriptsBridge.RegisterLoadCallback(this);
+
+        // We do not want the RecyclerView to be announced by screen readers every time
+        // the view is bound.
+        if (mRecyclerView.getAdapter() != mAdapter) {
+            mRecyclerView.setAdapter(mAdapter);
+            // Initialize script list.
+            mAdapter.onDataUpdated();
+        }
+    }
+
+    public void NotifyScriptsChanged() {
+        mAdapter.onDataUpdated();
+    }
+
+    public void OnUserScriptLoaded(boolean result, String error) {
+        if (result == false) {
+            Toast toast = Toast.makeText(getContext(), error, Toast.LENGTH_LONG);
+            toast.show();
+        }
+    }
+}
\ No newline at end of file
diff --git a/components/user_scripts/android/java/src/org/chromium/components/user_scripts/UserScriptsBridge.java b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/UserScriptsBridge.java
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/UserScriptsBridge.java
@@ -0,0 +1,178 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package org.chromium.components.user_scripts;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.lang.ref.WeakReference;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+import androidx.annotation.Nullable;
+
+import org.chromium.base.annotations.CalledByNative;
+import org.chromium.base.annotations.JNINamespace;
+import org.chromium.base.annotations.NativeMethods;
+import org.chromium.base.Log;
+import org.chromium.ui.base.WindowAndroid;
+
+import org.chromium.components.user_scripts.ScriptListPreference;
+import org.chromium.components.user_scripts.IUserScriptsUtils;
+
+@JNINamespace("user_scripts")
+public class UserScriptsBridge {
+    static WeakReference<ScriptListPreference> observer;
+
+    private static IUserScriptsUtils utilInstance;
+
+    public static void registerUtils(IUserScriptsUtils instance) {
+        utilInstance = instance;
+    }
+
+    public static IUserScriptsUtils getUtils() {
+        return utilInstance;
+    }
+
+    public static boolean isFeatureEnabled() {
+        return UserScriptsBridgeJni.get().isFeatureEnabled();
+    }
+
+    public static boolean isUserEnabled() {
+        return UserScriptsBridgeJni.get().isUserEnabled();
+    }
+
+    public static void setUserEnabled(boolean enabled) {
+        UserScriptsBridgeJni.get().setUserEnabled(enabled);
+    }
+
+    public static void RemoveScript(String key) {
+        UserScriptsBridgeJni.get().removeScript(key);
+    }
+
+    public static void SetScriptEnabled(String key,
+                                        boolean enabled) {
+        UserScriptsBridgeJni.get().setScriptEnabled(key, enabled);
+    }
+
+    public static void Reload() {
+        UserScriptsBridgeJni.get().reload();
+    }
+
+    public static void SelectAndAddScriptFromFile(WindowAndroid window) {
+        Context context = window.getContext().get();
+
+        Intent fileSelector = new Intent(Intent.ACTION_OPEN_DOCUMENT);
+        fileSelector.addCategory(Intent.CATEGORY_OPENABLE);
+        fileSelector.setType("*/*");
+        fileSelector.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
+
+        window.showIntent(fileSelector,
+            new WindowAndroid.IntentCallback() {
+                @Override
+                public void onIntentCompleted(WindowAndroid window, int resultCode, Intent data) {
+                    if (data == null) return;
+                    Uri filePath = data.getData();
+                    UserScriptsBridgeJni.get().tryToInstall(filePath.toString());
+                }
+            },
+            null);
+    }
+
+    public static void TryToInstall(String ScriptFullPath) {
+        UserScriptsBridgeJni.get().tryToInstall(ScriptFullPath);
+    }
+
+    public static List<ScriptInfo> getUserScriptItems() {
+        List<ScriptInfo> list = new ArrayList<>();
+        try {
+            String json = UserScriptsBridgeJni.get().getScriptsInfo();
+
+            JSONObject jsonObject = new JSONObject(json);
+
+            JSONArray scripts = jsonObject.names();
+            if (scripts != null) {
+                Log.i("User Scripts Loaded", json);
+                Log.i("Totals scripts", Integer.toString(scripts.length()));
+                for (int i = 0; i < scripts.length(); i++) {
+                    String key = (String) scripts.get(i);
+                    JSONObject script = jsonObject.getJSONObject(key);
+
+                    ScriptInfo si = new ScriptInfo();
+                    si.Key = key;
+                    list.add(si);
+
+                    if(script.has("name")) si.Name = script.getString("name");
+                    if(script.has("description")) si.Description = script.getString("description");
+                    if(script.has("version")) si.Version = script.getString("version");
+                    if(script.has("file_path")) si.FilePath = script.getString("file_path");
+                    if(script.has("url_source")) si.UrlSource = script.getString("url_source");
+                    si.Enabled = script.getBoolean("enabled");
+                }
+            }
+        } catch (Exception e) {
+            Log.e("User Scripts Load Error", e.toString());
+        }
+        return list;
+    }
+
+    public static void RegisterLoadCallback(ScriptListPreference caller) {
+        UserScriptsBridgeJni.get().registerLoadCallback();
+        observer = new WeakReference<ScriptListPreference>(caller);
+    }
+
+    @CalledByNative
+    private static void shouldRefreshUserScriptList() {
+        ScriptListPreference reference = observer.get();
+        if (reference != null) {
+            reference.NotifyScriptsChanged();
+        }
+    }
+
+    @CalledByNative
+    private static void onUserScriptLoaded(boolean result, String error) {
+        ScriptListPreference reference = observer.get();
+        if (reference != null) {
+            reference.OnUserScriptLoaded(result, error);
+        }
+    }
+
+    @NativeMethods
+    interface Natives {
+        boolean isFeatureEnabled();
+
+        boolean isUserEnabled();
+        void setUserEnabled(boolean enabled);
+
+        String getScriptsInfo();
+
+        void removeScript(String scriptKey);
+        void setScriptEnabled(String scriptKey, boolean enabled);
+
+        void reload();
+        void selectAndAddScriptFromFile(WindowAndroid window);
+        void tryToInstall(String scriptFullPath);
+
+        void registerLoadCallback();
+    }
+
+}
\ No newline at end of file
diff --git a/components/user_scripts/android/java/src/org/chromium/components/user_scripts/UserScriptsPreferences.java b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/UserScriptsPreferences.java
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/android/java/src/org/chromium/components/user_scripts/UserScriptsPreferences.java
@@ -0,0 +1,144 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package org.chromium.components.user_scripts;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.content.Context;
+import android.content.Intent;
+import android.content.DialogInterface;
+import android.os.Bundle;
+import android.provider.Browser;
+import android.net.Uri;
+import android.view.MenuItem;
+import android.view.View;
+
+import androidx.preference.Preference;
+import androidx.preference.PreferenceFragmentCompat;
+
+import org.chromium.base.Log;
+import org.chromium.ui.base.WindowAndroid;
+import org.chromium.ui.base.ActivityWindowAndroid;
+
+import org.chromium.components.browser_ui.settings.ChromeSwitchPreference;
+import org.chromium.components.browser_ui.settings.SettingsUtils;
+import org.chromium.components.browser_ui.settings.TextMessagePreference;
+
+import org.chromium.components.user_scripts.UserScriptsBridge;
+import org.chromium.components.user_scripts.FragmentWindowAndroid;
+
+public class UserScriptsPreferences
+        extends PreferenceFragmentCompat
+        implements SettingsUtils.ISupportHelpAndFeedback {
+
+    private static final String PREF_ENABLED_SWITCH = "enabled_switch";
+    private static final String PREF_SCRIPTLISTPREFERENCE = "script_list";
+    private static final String PREF_SCRIPTS_DISABLED_DESCRIPTION = "scripts_disabled_description";
+
+    public static final String EXTRA_SCRIPT_FILE = "org.chromium.chrome.preferences.script_file";
+
+    private FragmentWindowAndroid mwindowAndroid;
+
+    @Override
+    public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
+        getActivity().setTitle(R.string.prefs_userscripts_settings);
+        SettingsUtils.addPreferencesFromResource(this, R.xml.userscripts_preferences);
+
+        ChromeSwitchPreference enabledSwitch =
+                (ChromeSwitchPreference) findPreference(PREF_ENABLED_SWITCH);
+        ScriptListPreference listPreference =
+                (ScriptListPreference) findPreference(PREF_SCRIPTLISTPREFERENCE);
+
+        boolean enabled = UserScriptsBridge.isUserEnabled();
+        enabledSwitch.setChecked(enabled);
+        listPreference.setEnabled(enabled);
+        enabledSwitch.setOnPreferenceChangeListener((preference, newValue) -> {
+            UserScriptsBridge.setUserEnabled((boolean) newValue);
+            listPreference.setEnabled((boolean) newValue);
+            return true;
+        });
+
+        mwindowAndroid = new FragmentWindowAndroid(getContext(), this);
+        listPreference.setWindowAndroid(mwindowAndroid);
+
+        if (UserScriptsBridge.isFeatureEnabled() == false) {
+            enabledSwitch.setEnabled(false);
+            listPreference.setEnabled(false);
+
+            TextMessagePreference scripts_disabled_description =
+                (TextMessagePreference) findPreference(PREF_SCRIPTS_DISABLED_DESCRIPTION);
+            scripts_disabled_description.setVisible(true);
+        }
+    }
+
+    @Override
+    public void onActivityResult(int requestCode, int resultCode, Intent data) {
+        // handle picker callback from SelectFileDialog
+        mwindowAndroid.onActivityResult(requestCode, resultCode, data);
+    }
+
+    public void onHelpAndFeebackPressed() {
+        Context context = getContext();
+
+        Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://github.com/bromite/bromite/wiki/UserScripts"));
+        // Let Chromium know that this intent is from Chromium, so that it does not close the app when
+        // the user presses 'back' button.
+        intent.putExtra(Browser.EXTRA_APPLICATION_ID, context.getPackageName());
+        intent.putExtra(Browser.EXTRA_CREATE_NEW_TAB, true);
+        intent.setPackage(context.getPackageName());
+        context.startActivity(intent);
+    }
+
+    public static Bundle createFragmentArgsForInstall(String filePath) {
+        Bundle fragmentArgs = new Bundle();
+        fragmentArgs.putSerializable(EXTRA_SCRIPT_FILE, filePath);
+        return fragmentArgs;
+    }
+
+    @Override
+    public void onActivityCreated(Bundle savedInstanceState) {
+        super.onActivityCreated(savedInstanceState);
+
+        String scriptToInstall = (String)getArguments().getSerializable(EXTRA_SCRIPT_FILE);
+        if (scriptToInstall != null) {
+            DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() {
+                @Override
+                public void onClick(DialogInterface dialog, int which) {
+                    switch (which){
+                        case DialogInterface.BUTTON_POSITIVE:
+                            UserScriptsBridge.TryToInstall(scriptToInstall);
+                            break;
+
+                        case DialogInterface.BUTTON_NEGATIVE:
+                            break;
+                    }
+                }
+            };
+
+            Context context = getContext();
+            String message = context.getString(R.string.ask_to_install) + " " +
+                             scriptToInstall;
+
+            AlertDialog.Builder builder = new AlertDialog.Builder(context);
+            builder.setMessage(message)
+                .setPositiveButton(context.getString(R.string.yes), dialogClickListener)
+                .setNegativeButton(context.getString(R.string.no), dialogClickListener)
+                .show();
+        }
+    }
+}
diff --git a/components/user_scripts/android/java_sources.gni b/components/user_scripts/android/java_sources.gni
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/java_sources.gni
@@ -0,0 +1,18 @@
+# This file is part of Bromite.
+
+# Bromite is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# Bromite is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+
+userscripts_java_sources = [
+  "//components/user_scripts/android/java/src/org/chromium/chrome/browser/user_scripts/UserScriptsUtils.java",
+]
diff --git a/components/user_scripts/android/user_scripts_bridge.cc b/components/user_scripts/android/user_scripts_bridge.cc
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/user_scripts_bridge.cc
@@ -0,0 +1,179 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <jni.h>
+#include <algorithm>
+#include <string>
+#include <vector>
+#include <sstream>
+#include <iterator>
+
+#include "base/android/callback_android.h"
+#include "base/android/jni_android.h"
+#include "base/android/jni_array.h"
+#include "base/android/jni_string.h"
+#include "base/android/scoped_java_ref.h"
+#include "components/embedder_support/android/browser_context/browser_context_handle.h"
+#include "ui/android/window_android.h"
+
+#include "components/user_scripts/android/user_scripts_jni_headers/UserScriptsBridge_jni.h"
+#include "../browser/userscripts_browser_client.h"
+#include "user_scripts_bridge.h"
+
+using base::android::AttachCurrentThread;
+using base::android::ConvertJavaStringToUTF8;
+using base::android::ConvertUTF16ToJavaString;
+using base::android::ConvertUTF8ToJavaString;
+using base::android::JavaParamRef;
+using base::android::JavaRef;
+using base::android::ScopedJavaGlobalRef;
+using base::android::ScopedJavaLocalRef;
+using content::BrowserContext;
+
+namespace {
+
+user_scripts::UserScriptsBrowserClient* GetUserScriptsBrowserClient() {
+  return user_scripts::UserScriptsBrowserClient::GetInstance();
+}
+
+class CallbackObserver : public user_scripts::UserScriptLoader::Observer {
+  private:
+    void OnScriptsLoaded(user_scripts::UserScriptLoader* loader,
+                         content::BrowserContext* browser_context) override {
+        user_scripts::ShouldRefreshUserScriptList(base::android::AttachCurrentThread());
+    }
+
+    void OnUserScriptLoaded(user_scripts::UserScriptLoader* loader,
+                            bool result, const std::string& error) override {
+        user_scripts::OnUserScriptLoaded(base::android::AttachCurrentThread(),
+          result, error);
+    }
+
+    void OnUserScriptLoaderDestroyed(user_scripts::UserScriptLoader* loader) override {}
+};
+
+CallbackObserver* g_userscripts_loader_observer = NULL;
+
+}
+
+namespace user_scripts {
+
+static jboolean JNI_UserScriptsBridge_IsFeatureEnabled(
+                    JNIEnv* env) {
+  return GetUserScriptsBrowserClient() != NULL;
+}
+
+static jboolean JNI_UserScriptsBridge_IsUserEnabled(
+                    JNIEnv* env) {
+  user_scripts::UserScriptsBrowserClient* client = GetUserScriptsBrowserClient();
+  if (client == NULL) return false;
+  return client->GetPrefs()->IsEnabled();
+}
+
+static void JNI_UserScriptsBridge_SetUserEnabled(
+                    JNIEnv* env,
+                    jboolean is_enabled) {
+  user_scripts::UserScriptsBrowserClient* client = GetUserScriptsBrowserClient();
+  if (client == NULL) return;
+  client->GetPrefs()->SetEnabled(is_enabled);
+  client->GetLoader()->StartLoad();
+}
+
+static base::android::ScopedJavaLocalRef<jstring> JNI_UserScriptsBridge_GetScriptsInfo(
+                    JNIEnv* env) {
+  user_scripts::UserScriptsBrowserClient* client = GetUserScriptsBrowserClient();
+  if (client == NULL) return ConvertUTF8ToJavaString(env, {});
+
+  std::string json = client->GetPrefs()->GetScriptsInfo();
+  return ConvertUTF8ToJavaString(env, json);
+}
+
+static void JNI_UserScriptsBridge_RemoveScript(
+                    JNIEnv* env,
+                    const JavaParamRef<jstring>& jscript_key) {
+  user_scripts::UserScriptsBrowserClient* client = GetUserScriptsBrowserClient();
+  if (client == NULL) return;
+
+  std::string script_key = base::android::ConvertJavaStringToUTF8(jscript_key);
+  client->GetLoader()->RemoveScript(script_key);
+}
+
+static void JNI_UserScriptsBridge_SetScriptEnabled(
+                    JNIEnv* env,
+                    const JavaParamRef<jstring>& jscript_key,
+                    jboolean is_enabled) {
+  user_scripts::UserScriptsBrowserClient* client = GetUserScriptsBrowserClient();
+  if (client == NULL) return;
+
+  std::string script_key = base::android::ConvertJavaStringToUTF8(jscript_key);
+  client->GetLoader()->SetScriptEnabled(script_key, is_enabled);
+}
+
+static void JNI_UserScriptsBridge_Reload(
+                    JNIEnv* env) {
+  user_scripts::UserScriptsBrowserClient* client = GetUserScriptsBrowserClient();
+  if (client == NULL) return;
+
+  client->GetLoader()->StartLoad();
+  user_scripts::ShouldRefreshUserScriptList(env);
+}
+
+static void JNI_UserScriptsBridge_SelectAndAddScriptFromFile(
+                    JNIEnv* env,
+                    const JavaParamRef<jobject>& jwindow_android) {
+  user_scripts::UserScriptsBrowserClient* client = GetUserScriptsBrowserClient();
+  if (client == NULL) return;
+
+  client->GetLoader()->SelectAndAddScriptFromFile(
+                    ui::WindowAndroid::FromJavaWindowAndroid(jwindow_android));
+}
+
+static void JNI_UserScriptsBridge_TryToInstall(JNIEnv* env,
+                         const JavaParamRef<jstring>& jscript_path) {
+  user_scripts::UserScriptsBrowserClient* client = GetUserScriptsBrowserClient();
+  if (client == NULL) return;
+
+  std::string script_path = base::android::ConvertJavaStringToUTF8(jscript_path);
+  base::FilePath path(script_path);
+
+  client->GetLoader()->TryToInstall(path);
+}
+
+static void JNI_UserScriptsBridge_RegisterLoadCallback(
+                    JNIEnv* env) {
+  user_scripts::UserScriptsBrowserClient* client = GetUserScriptsBrowserClient();
+  if (client == NULL) return;
+
+  if( g_userscripts_loader_observer == NULL ) {
+    g_userscripts_loader_observer = new CallbackObserver();
+    client->GetLoader()->AddObserver(g_userscripts_loader_observer);
+  }
+}
+
+static void ShouldRefreshUserScriptList(JNIEnv* env) {
+  Java_UserScriptsBridge_shouldRefreshUserScriptList(env);
+}
+
+static void OnUserScriptLoaded(JNIEnv* env,
+              bool result, const std::string& error) {
+  base::android::ScopedJavaLocalRef<jstring> j_error =
+    base::android::ConvertUTF8ToJavaString(env, error);
+
+  Java_UserScriptsBridge_onUserScriptLoaded(env, result, j_error);
+}
+
+}
\ No newline at end of file
diff --git a/components/user_scripts/android/user_scripts_bridge.h b/components/user_scripts/android/user_scripts_bridge.h
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/android/user_scripts_bridge.h
@@ -0,0 +1,31 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef COMPONENTS_USERSCRIPS_HELPER_ANDROID_H_
+#define COMPONENTS_USERSCRIPS_HELPER_ANDROID_H_
+
+#include <jni.h>
+
+namespace user_scripts {
+
+static void ShouldRefreshUserScriptList(JNIEnv* env);
+static void OnUserScriptLoaded(JNIEnv* env,
+              bool result, const std::string& error);
+
+}  // namespace user_scripts
+
+#endif
\ No newline at end of file
diff --git a/components/user_scripts/browser/BUILD.gn b/components/user_scripts/browser/BUILD.gn
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/browser/BUILD.gn
@@ -0,0 +1,91 @@
+# This file is part of Bromite.
+
+# Bromite is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# Bromite is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+
+import("//build/config/features.gni")
+import("//tools/grit/grit_rule.gni")
+
+group("browser") {
+  public_deps = [
+    "//components/user_scripts/browser:browser_sources",
+  ]
+}
+
+source_set("browser_sources") {
+  visibility = [ "./*" ]
+
+  sources = [
+    "file_task_runner.cc",
+    "file_task_runner.h",
+    "userscripts_browser_client.cc",
+    "userscripts_browser_client.h",
+    "user_script_loader.cc",
+    "user_script_loader.h",
+    "user_script_prefs.cc",
+    "user_script_prefs.h",
+    "user_script_pref_info.cc",
+    "user_script_pref_info.h",
+    "ui/user_scripts_ui.h",
+    "ui/user_scripts_ui.cc",
+  ]
+
+  deps = [
+    ":userscripts_browser_resources",
+    "//base:i18n",
+    "//components/keyed_service/content",
+    "//components/keyed_service/core",
+    "//components/pref_registry",
+    "//components/prefs",
+    "//content/public/browser",
+    "//crypto:platform",
+    "//components/user_scripts/common",
+    "//services/device/public/mojom",
+    "//services/preferences/public/cpp",
+    "//services/service_manager/public/cpp",
+    "//third_party/blink/public/common",
+    "//third_party/blink/public/mojom/frame",
+    "//ui/display",
+  ]
+
+  public_deps = [
+    "//content/public/common",
+  ]
+
+  configs += [
+    "//build/config:precompiled_headers",
+
+    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+    "//build/config/compiler:no_size_t_to_int_warning",
+    "//build/config/compiler:wexit_time_destructors",
+  ]
+}
+
+group("closure_compile") {
+  deps = [ "resources/user-script-ui:closure_compile" ]
+}
+
+grit("userscripts_browser_resources") {
+  source = "resources/browser_resources.grd"
+
+  output_dir = "$root_gen_dir/chrome"
+  outputs = [
+    "grit/userscripts_browser_resources.h",
+    "userscripts_browser_resources.pak",
+  ]
+
+  deps = [
+    "//chrome/browser/resources/web_app_internals:components",
+    "//chrome/browser/ui/webui/internals/web_app:mojo_bindings_js",
+  ]
+}
diff --git a/components/user_scripts/browser/file_task_runner.cc b/components/user_scripts/browser/file_task_runner.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/browser/file_task_runner.cc
@@ -0,0 +1,40 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "file_task_runner.h"
+
+#include "base/sequenced_task_runner.h"
+#include "base/task/lazy_thread_pool_task_runner.h"
+#include "base/task/task_traits.h"
+
+namespace user_scripts {
+
+namespace {
+
+base::LazyThreadPoolSequencedTaskRunner g_us_task_runner =
+    LAZY_THREAD_POOL_SEQUENCED_TASK_RUNNER_INITIALIZER(
+        base::TaskTraits(base::MayBlock(),
+                         base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN,
+                         base::TaskPriority::USER_VISIBLE));
+
+}  // namespace
+
+scoped_refptr<base::SequencedTaskRunner> GetUserScriptsFileTaskRunner() {
+  return g_us_task_runner.Get();
+}
+
+}  // namespace user_scripts
diff --git a/components/user_scripts/browser/file_task_runner.h b/components/user_scripts/browser/file_task_runner.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/browser/file_task_runner.h
@@ -0,0 +1,34 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef USERSCRIPTS_BROWSER_FILE_TASK_RUNNER_H_
+#define USERSCRIPTS_BROWSER_FILE_TASK_RUNNER_H_
+
+#include "base/memory/ref_counted.h"
+#include "base/task/task_traits.h"
+
+namespace base {
+class SequencedTaskRunner;
+}
+
+namespace user_scripts {
+
+scoped_refptr<base::SequencedTaskRunner> GetUserScriptsFileTaskRunner();
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_BROWSER_FILE_TASK_RUNNER_H_
diff --git a/components/user_scripts/browser/resources/browser_resources.grd b/components/user_scripts/browser/resources/browser_resources.grd
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/resources/browser_resources.grd
@@ -0,0 +1,14 @@
+<grit latest_public_release="0" current_release="1" output_all_resource_defines="false">
+  <outputs>
+    <output filename="grit/userscripts_browser_resources.h" type="rc_header">
+      <emit emit_type='prepend'></emit>
+    </output>
+    <output filename="userscripts_browser_resources.pak" type="data_package" />
+  </outputs>
+  <release seq="1">
+    <includes>
+      <include name="IDR_USER_SCRIPTS_HTML" file="user-script-ui\user-scripts-ui.html" type="BINDATA" />
+      <include name="IDR_USER_SCRIPTS_JS" file="user-script-ui\user-scripts-ui.js" type="BINDATA" />
+    </includes>
+  </release>
+</grit>
\ No newline at end of file
diff --git a/components/user_scripts/browser/resources/user-script-ui/BUILD.gn b/components/user_scripts/browser/resources/user-script-ui/BUILD.gn
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/resources/user-script-ui/BUILD.gn
@@ -0,0 +1,12 @@
+import("//third_party/closure_compiler/compile_js.gni")
+
+js_type_check("closure_compile") {
+  deps = [ ":view_script_source" ]
+}
+
+js_library("view_script_source") {
+  deps = [
+    "//ui/webui/resources/js:cr.m",
+    "//ui/webui/resources/js:util.m",
+  ]
+}
\ No newline at end of file
diff --git a/components/user_scripts/browser/resources/user-script-ui/user-scripts-ui.html b/components/user_scripts/browser/resources/user-script-ui/user-scripts-ui.html
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/resources/user-script-ui/user-scripts-ui.html
@@ -0,0 +1,14 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <title>Local State Debug Page</title>
+  <link rel="stylesheet" href="chrome://resources/css/text_defaults.css">
+  <script type="module" src="user-scripts-ui.js"></script>
+</head>
+<body>
+  <pre id="content">
+    Loading Script Source file...
+  </pre>
+</body>
+</html>
\ No newline at end of file
diff --git a/components/user_scripts/browser/resources/user-script-ui/user-scripts-ui.js b/components/user_scripts/browser/resources/user-script-ui/user-scripts-ui.js
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/resources/user-script-ui/user-scripts-ui.js
@@ -0,0 +1,9 @@
+import {sendWithPromise} from 'chrome://resources/js/cr.m.js';
+import {$} from 'chrome://resources/js/util.m.js';
+
+document.addEventListener('DOMContentLoaded', function() {
+  const urlParams = new URLSearchParams(window.location.search);
+  sendWithPromise('requestSource', urlParams.get('key')).then(textContent => {
+    $('content').textContent = textContent[0].content;
+  });
+});
\ No newline at end of file
diff --git a/components/user_scripts/browser/ui/user_scripts_ui.cc b/components/user_scripts/browser/ui/user_scripts_ui.cc
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/ui/user_scripts_ui.cc
@@ -0,0 +1,150 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+
+#include <memory>
+
+#include "base/bind.h"
+#include "base/json/json_string_value_serializer.h"
+#include "base/macros.h"
+#include "base/memory/writable_shared_memory_region.h"
+#include "base/strings/string_util.h"
+#include "base/values.h"
+
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/url_constants.h"
+#include "chrome/grit/userscripts_browser_resources.h"
+#include "components/prefs/pref_service.h"
+#include "content/public/browser/web_ui.h"
+#include "content/public/browser/web_ui_controller.h"
+#include "content/public/browser/web_ui_data_source.h"
+#include "content/public/browser/web_ui_message_handler.h"
+
+#include "user_scripts_ui.h"
+#include "../userscripts_browser_client.h"
+#include "../../common/user_script.h"
+
+namespace {
+
+class UserScriptsUIHandler : public content::WebUIMessageHandler {
+ public:
+  UserScriptsUIHandler();
+  ~UserScriptsUIHandler() override;
+
+  // content::WebUIMessageHandler:
+  void RegisterMessages() override;
+
+ private:
+  void HandleRequestSource(const base::ListValue* args);
+  void OnScriptsLoaded(
+      const std::string callback_id,
+      const std::string script_key,
+      std::unique_ptr<user_scripts::UserScriptList> user_scripts,
+      base::ReadOnlySharedMemoryRegion shared_memory);
+
+  std::unique_ptr<user_scripts::UserScriptList> loaded_scripts_;
+
+  base::WeakPtrFactory<UserScriptsUIHandler> weak_factory_{this};
+
+  DISALLOW_COPY_AND_ASSIGN(UserScriptsUIHandler);
+};
+
+UserScriptsUIHandler::UserScriptsUIHandler()
+  : loaded_scripts_(new user_scripts::UserScriptList()) {
+}
+
+UserScriptsUIHandler::~UserScriptsUIHandler() {
+}
+
+void UserScriptsUIHandler::RegisterMessages() {
+  web_ui()->RegisterMessageCallback(
+      "requestSource",
+      base::BindRepeating(&UserScriptsUIHandler::HandleRequestSource,
+                          base::Unretained(this)));
+}
+
+void UserScriptsUIHandler::HandleRequestSource(const base::ListValue* args) {
+  AllowJavascript();
+  std::string callback_id;
+  CHECK(args->GetString(0, &callback_id));
+
+  std::string script_key;
+  if (args->GetString(1, &script_key) == false) {
+    std::string json = "Missing key value.";
+    ResolveJavascriptCallback(base::Value(callback_id), base::Value(json));
+    return;
+  }
+
+  user_scripts::UserScriptsBrowserClient* client = user_scripts::UserScriptsBrowserClient::GetInstance();
+  if (client == NULL) {
+    std::string json = "User scripts disabled.";
+    ResolveJavascriptCallback(base::Value(callback_id), base::Value(json));
+  } else {
+    std::unique_ptr<user_scripts::UserScriptList> scripts_to_load =
+                                    std::move(loaded_scripts_);
+    scripts_to_load->clear();
+
+    client->GetLoader()->LoadScripts(std::move(scripts_to_load),
+      base::BindOnce(
+          &UserScriptsUIHandler::OnScriptsLoaded,
+          weak_factory_.GetWeakPtr(),
+          callback_id, script_key)
+      );
+  }
+}
+
+void UserScriptsUIHandler::OnScriptsLoaded(
+    const std::string callback_id,
+    const std::string script_key,
+    std::unique_ptr<user_scripts::UserScriptList> user_scripts,
+    base::ReadOnlySharedMemoryRegion shared_memory) {
+  loaded_scripts_ = std::move(user_scripts);
+
+  base::ListValue response;
+  for (const std::unique_ptr<user_scripts::UserScript>& script : *loaded_scripts_) {
+    if (script->key() == script_key) {
+      auto scriptData = std::make_unique<base::DictionaryValue>();
+      for (const std::unique_ptr<user_scripts::UserScript::File>& js_file :
+          script->js_scripts()) {
+        base::StringPiece contents = js_file->GetContent();
+        scriptData->SetString("content", contents.data());
+      }
+      response.Append(std::move(scriptData));
+    }
+  }
+
+  ResolveJavascriptCallback(base::Value(callback_id), response);
+}
+
+}  // namespace
+
+namespace user_scripts {
+
+UserScriptsUI::UserScriptsUI(content::WebUI* web_ui) : WebUIController(web_ui) {
+  content::WebUIDataSource* html_source =
+      content::WebUIDataSource::Create(kChromeUIUserScriptsHost);
+  html_source->SetDefaultResource(IDR_USER_SCRIPTS_HTML);
+  html_source->AddResourcePath("user-scripts-ui.js", IDR_USER_SCRIPTS_JS);
+  content::WebUIDataSource::Add(Profile::FromWebUI(web_ui), html_source);
+  web_ui->AddMessageHandler(std::make_unique<UserScriptsUIHandler>());
+}
+
+UserScriptsUI::~UserScriptsUI() {
+}
+
+}
\ No newline at end of file
diff --git a/components/user_scripts/browser/ui/user_scripts_ui.h b/components/user_scripts/browser/ui/user_scripts_ui.h
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/ui/user_scripts_ui.h
@@ -0,0 +1,39 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef USERSCRIPTS_BROWSER_UI_USER_SCRIPTS_UI_H_
+#define USERSCRIPTS_BROWSER_UI_USER_SCRIPTS_UI_H_
+
+#include "base/macros.h"
+#include "content/public/browser/web_ui_controller.h"
+
+namespace user_scripts {
+
+const char kChromeUIUserScriptsHost[] = "user-scripts";
+
+class UserScriptsUI : public content::WebUIController {
+ public:
+  explicit UserScriptsUI(content::WebUI* web_ui);
+  ~UserScriptsUI() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(UserScriptsUI);
+};
+
+}
+
+#endif
\ No newline at end of file
diff --git a/components/user_scripts/browser/user_script_loader.cc b/components/user_scripts/browser/user_script_loader.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/browser/user_script_loader.cc
@@ -0,0 +1,657 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "user_script_loader.h"
+
+#include <stddef.h>
+
+#include <set>
+#include <string>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/memory/writable_shared_memory_region.h"
+#include "base/strings/string_util.h"
+#include "base/version.h"
+#include "base/task/task_traits.h"
+#include "base/files/file_util.h"
+#include "base/files/file_enumerator.h"
+#include "base/path_service.h"
+#include "base/base_paths_android.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/android/content_uri_utils.h"
+#include "base/android/jni_android.h"
+
+#include "crypto/sha2.h"
+#include "base/base64.h"
+
+#include "build/build_config.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_task_traits.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_types.h"
+#include "content/public/browser/render_process_host.h"
+#include "ui/shell_dialogs/select_file_dialog.h"
+#include "content/browser/file_system_access/file_system_chooser.h"
+#include "chrome/browser/ui/chrome_select_file_policy.h"
+#include "ui/android/window_android.h"
+
+#include "../common/user_scripts_features.h"
+#include "../common/extension_messages.h"
+#include "file_task_runner.h"
+#include "user_script_prefs.h"
+#include "user_script_pref_info.h"
+
+using content::BrowserThread;
+using content::BrowserContext;
+
+namespace user_scripts {
+
+namespace {
+
+bool invalidChar(unsigned char c)
+{
+  return !(c>=0 && c <128);
+}
+
+void stripUnicode(std::string& str)
+{
+  str.erase(remove_if(str.begin(),str.end(), invalidChar), str.end());
+}
+
+// Helper function to parse greasesmonkey headers
+bool GetDeclarationValue(const base::StringPiece& line,
+                         const base::StringPiece& prefix,
+                         std::string* value) {
+  base::StringPiece::size_type index = line.find(prefix);
+  if (index == base::StringPiece::npos)
+    return false;
+
+  std::string temp(line.data() + index + prefix.length(),
+                   line.length() - index - prefix.length());
+
+  if (temp.empty() || !base::IsUnicodeWhitespace(temp[0]))
+    return false;
+
+  base::TrimWhitespaceASCII(temp, base::TRIM_ALL, value);
+  return true;
+}
+
+}  // namespace
+
+// static
+bool UserScriptLoader::ParseMetadataHeader(const base::StringPiece& script_text,
+                                           std::unique_ptr<UserScript>& script,
+                                           std::string& error_message) {
+  // http://wiki.greasespot.net/Metadata_block
+  base::StringPiece line;
+  size_t line_start = 0;
+  size_t line_end = line_start;
+  bool in_metadata = false;
+
+  static const base::StringPiece kUserScriptBegin("// ==UserScript==");
+  static const base::StringPiece kUserScriptEng("// ==/UserScript==");
+  static const base::StringPiece kNamespaceDeclaration("// @namespace");
+  static const base::StringPiece kNameDeclaration("// @name");
+  static const base::StringPiece kVersionDeclaration("// @version");
+  static const base::StringPiece kDescriptionDeclaration("// @description");
+  static const base::StringPiece kIncludeDeclaration("// @include");
+  static const base::StringPiece kExcludeDeclaration("// @exclude");
+  static const base::StringPiece kMatchDeclaration("// @match");
+  static const base::StringPiece kExcludeMatchDeclaration("// @exclude_match");
+  static const base::StringPiece kRunAtDeclaration("// @run-at");
+  static const base::StringPiece kRunAtDocumentStartValue("document-start");
+  static const base::StringPiece kRunAtDocumentEndValue("document-end");
+  static const base::StringPiece kRunAtDocumentIdleValue("document-idle");
+  static const base::StringPiece kUrlSourceDeclaration("// @url");
+
+  while (line_start < script_text.length()) {
+    line_end = script_text.find('\n', line_start);
+
+    // Handle the case where there is no trailing newline in the file.
+    if (line_end == std::string::npos)
+      line_end = script_text.length() - 1;
+
+    line = base::StringPiece(script_text.data() + line_start,
+                             line_end - line_start);
+
+    if (!in_metadata) {
+      if (base::StartsWith(line, kUserScriptBegin))
+        in_metadata = true;
+    } else {
+      if (base::StartsWith(line, kUserScriptEng))
+        break;
+
+      std::string value;
+      if (GetDeclarationValue(line, kIncludeDeclaration, &value)) {
+        // We escape some characters that MatchPattern() considers special.
+        base::ReplaceSubstringsAfterOffset(&value, 0, "\\", "\\\\");
+        base::ReplaceSubstringsAfterOffset(&value, 0, "?", "\\?");
+        script->add_glob(value);
+      } else if (GetDeclarationValue(line, kExcludeDeclaration, &value)) {
+        base::ReplaceSubstringsAfterOffset(&value, 0, "\\", "\\\\");
+        base::ReplaceSubstringsAfterOffset(&value, 0, "?", "\\?");
+        script->add_exclude_glob(value);
+      } else if (GetDeclarationValue(line, kNamespaceDeclaration, &value)) {
+        script->set_name_space(value);
+      } else if (GetDeclarationValue(line, kNameDeclaration, &value)) {
+        script->set_name(value);
+      } else if (GetDeclarationValue(line, kVersionDeclaration, &value)) {
+        base::Version version(value);
+        if (version.IsValid())
+          script->set_version(version.GetString());
+      } else if (GetDeclarationValue(line, kDescriptionDeclaration, &value)) {
+        script->set_description(value);
+      } else if (GetDeclarationValue(line, kMatchDeclaration, &value)) {
+        URLPattern pattern(UserScript::ValidUserScriptSchemes());
+        if (URLPattern::ParseResult::kSuccess != pattern.Parse(value)) {
+          error_message = "Invalid UserScript Schema " + value;
+          return false;
+        }
+        script->add_url_pattern(pattern);
+      } else if (GetDeclarationValue(line, kExcludeMatchDeclaration, &value)) {
+        URLPattern exclude(UserScript::ValidUserScriptSchemes());
+        if (URLPattern::ParseResult::kSuccess != exclude.Parse(value)) {
+          error_message = "Invalid UserScript Schema " + value;
+          return false;
+        }
+        script->add_exclude_url_pattern(exclude);
+      } else if (GetDeclarationValue(line, kRunAtDeclaration, &value)) {
+        if (value == kRunAtDocumentStartValue)
+          script->set_run_location(UserScript::DOCUMENT_START);
+        else if (value == kRunAtDocumentEndValue)
+          script->set_run_location(UserScript::DOCUMENT_END);
+        else if (value == kRunAtDocumentIdleValue)
+          script->set_run_location(UserScript::DOCUMENT_IDLE);
+        else {
+          error_message = "Invalid RunAtDeclaration " + value;
+          return false;
+        }
+      } else if(GetDeclarationValue(line, kUrlSourceDeclaration, &value)) {
+        script->set_url_source(value);
+      }
+
+      // TODO(aa): Handle more types of metadata.
+    }
+
+    line_start = line_end + 1;
+  }
+
+  // If no patterns were specified, default to @include *. This is what
+  // Greasemonkey does.
+  if (script->globs().empty() && script->url_patterns().is_empty())
+    script->add_glob("*");
+
+  return true;
+}
+
+// static
+bool LoadUserScriptFromFile(
+    const base::FilePath& user_script_path, const GURL& original_url,
+    std::unique_ptr<UserScript>& script,
+    base::string16* error) {
+
+    std::string script_key = user_script_path.BaseName().value();
+
+    std::string content;
+    if (user_script_path.IsContentUri()) {
+      if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+        LOG(INFO) << "UserScriptLoader: path " << user_script_path << " is a content uri";
+
+      base::FilePath tempFilePath;
+      if( base::CreateTemporaryFile(&tempFilePath) == false ) {
+        *error = base::ASCIIToUTF16("Could not read create temp file.");
+        return false;
+      }
+
+      if( base::CopyFile(user_script_path, tempFilePath) == false ) {
+        *error = base::ASCIIToUTF16("Could not copy file to temp file.");
+        return false;
+      }
+
+      if (!base::ReadFileToString(tempFilePath, &content)) {
+        *error = base::ASCIIToUTF16("Could not read source file from temp path.");
+        return false;
+      }
+    } else {
+      if (!base::ReadFileToString(user_script_path, &content)) {
+        *error = base::ASCIIToUTF16("Could not read source file.");
+        return false;
+      }
+    }
+
+    if (!base::IsStringUTF8(content)) {
+      *error = base::ASCIIToUTF16("User script must be UTF8 encoded.");
+      return false;
+    }
+
+    std::string detailed_error;
+    if (!UserScriptLoader::ParseMetadataHeader(content, script, detailed_error)) {
+      *error = base::ASCIIToUTF16("Invalid script header. " + detailed_error);
+      return false;
+    }
+
+    // add into key the filename
+    // this value is used in ui to discriminate scripts
+    script->set_key(script_key);
+
+    script->set_match_origin_as_fallback(MatchOriginAsFallbackBehavior::kNever);
+
+    // remove unicode chars and set content into File
+    stripUnicode(content);
+    std::unique_ptr<UserScript::File> file(new UserScript::File());
+    file->set_content(content);
+    file->set_url(GURL(/*script_key*/ "script.js")); // name doesn't matter
+
+    // create SHA256 of file
+    char raw[crypto::kSHA256Length] = {0};
+    std::string key;
+    crypto::SHA256HashString(content, raw, crypto::kSHA256Length);
+    base::Base64Encode(base::StringPiece(raw, crypto::kSHA256Length), &key);
+    file->set_key(key);
+
+    script->js_scripts().push_back(std::move(file));
+
+    return true;
+}
+
+// static
+bool GetOrCreatePath(base::FilePath& path) {
+  base::PathService::Get(base::DIR_ANDROID_APP_DATA, &path);
+  path = path.AppendASCII("userscripts");
+
+  // create snippets directory if not exists
+  if(!base::PathExists(path)) {
+    LOG(INFO) << "Path " << path << " doesn't exists. Creating";
+    base::File::Error error = base::File::FILE_OK;
+    if( !base::CreateDirectoryAndGetError(path, &error) ) {
+      LOG(ERROR) <<
+               "UserScriptLoader: failed to create directory: " << path
+               << " with error code " << error;
+      return false;
+    }
+  }
+  return true;
+}
+
+// static
+void LoadUserScripts(UserScriptList* user_scripts_list) {
+  base::FilePath path;
+  if (GetOrCreatePath(path) == false) return;
+
+  // enumerate all files from script path
+  // we accept all files, but we check if it's a real
+  // userscript
+  base::FileEnumerator dir_enum(
+    path,
+    /*recursive=*/false, base::FileEnumerator::FILES);
+  base::FilePath full_name;
+  while (full_name = dir_enum.Next(), !full_name.empty()) {
+    std::unique_ptr<UserScript> userscript(new UserScript());
+
+    base::string16 error;
+    if (LoadUserScriptFromFile(full_name, GURL(), userscript, &error)) {
+      if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+        LOG(INFO) << "UserScriptLoader: Found user script " << userscript->name() <<
+              "-" << userscript->version() <<
+              "-" << userscript->description();
+
+      userscript->set_file_path(full_name.AsUTF8Unsafe());
+      user_scripts_list->push_back(std::move(userscript));
+    } else {
+      LOG(ERROR) << "UserScriptLoader: load error " << error;
+    }
+  }
+}
+
+UserScriptLoader::UserScriptLoader(BrowserContext* browser_context,
+                                   UserScriptsPrefs* prefs)
+    : loaded_scripts_(new UserScriptList()),
+      ready_(false),
+      browser_context_(browser_context),
+      prefs_(prefs) {}
+
+UserScriptLoader::~UserScriptLoader() {
+  for (auto& observer : observers_)
+     observer.OnUserScriptLoaderDestroyed(this);
+}
+
+void UserScriptLoader::OnRenderProcessHostCreated(
+    content::RenderProcessHost* process_host) {
+  if (initial_load_complete()) {
+    SendUpdate(process_host, shared_memory_);
+  }
+}
+
+void UserScriptLoader::AttemptLoad() {
+  int tryOut = prefs_->GetCurrentStartupTryout();
+  if (tryOut >= 3) {
+    LOG(INFO) << "UserScriptLoader: Possible crash detected. UserScript disabled";
+    prefs_->SetEnabled(false);
+  } else {
+    prefs_->StartupTryout(tryOut+1);
+    StartLoad();
+  }
+}
+
+void UserScriptLoader::StartLoad() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+    LOG(INFO) << "UserScriptLoader: StartLoad";
+
+  // Reload any loaded scripts, and clear out |loaded_scripts_| to indicate that
+  // the scripts aren't currently ready.
+  std::unique_ptr<UserScriptList> scripts_to_load = std::move(loaded_scripts_);
+  scripts_to_load->clear();
+
+  LoadScripts(std::move(scripts_to_load),
+              base::BindOnce(&UserScriptLoader::OnScriptsLoaded,
+                             weak_factory_.GetWeakPtr()));
+}
+
+// static
+base::ReadOnlySharedMemoryRegion UserScriptLoader::Serialize(
+    const UserScriptList& scripts) {
+  base::Pickle pickle;
+  pickle.WriteUInt32(scripts.size());
+  for (const std::unique_ptr<UserScript>& script : scripts) {
+    // TODO(aa): This can be replaced by sending content script metadata to
+    // renderers along with other extension data in ExtensionMsg_Loaded.
+    // See crbug.com/70516.
+    script->Pickle(&pickle);
+    // Write scripts as 'data' so that we can read it out in the slave without
+    // allocating a new string.
+    for (const std::unique_ptr<UserScript::File>& js_file :
+         script->js_scripts()) {
+      base::StringPiece contents = js_file->GetContent();
+      pickle.WriteData(contents.data(), contents.length());
+    }
+    for (const std::unique_ptr<UserScript::File>& css_file :
+         script->css_scripts()) {
+      base::StringPiece contents = css_file->GetContent();
+      pickle.WriteData(contents.data(), contents.length());
+    }
+  }
+
+  // Create the shared memory object.
+  base::MappedReadOnlyRegion shared_memory =
+      base::ReadOnlySharedMemoryRegion::Create(pickle.size());
+  if (!shared_memory.IsValid())
+    return {};
+
+  // Copy the pickle to shared memory.
+  memcpy(shared_memory.mapping.memory(), pickle.data(), pickle.size());
+  return std::move(shared_memory.region);
+}
+
+void UserScriptLoader::AddObserver(Observer* observer) {
+   observers_.AddObserver(observer);
+}
+
+void UserScriptLoader::RemoveObserver(Observer* observer) {
+   observers_.RemoveObserver(observer);
+}
+
+void UserScriptLoader::SetReady(bool ready) {
+  bool was_ready = ready_;
+  ready_ = ready;
+  if (ready_ && !was_ready)
+    AttemptLoad();
+}
+
+void UserScriptLoader::OnScriptsLoaded(
+    std::unique_ptr<UserScriptList> user_scripts,
+    base::ReadOnlySharedMemoryRegion shared_memory) {
+
+  if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+    LOG(INFO) << "UserScriptLoader: OnScriptsLoaded";
+
+  // Check user preferences for loaded user scripts
+  prefs_->CompareWithPrefs(*user_scripts);
+  loaded_scripts_ = std::move(user_scripts);
+
+  shared_memory =
+      UserScriptLoader::Serialize(*loaded_scripts_);
+
+  if (!shared_memory.IsValid()) {
+    // This can happen if we run out of file descriptors.  In that case, we
+    // have a choice between silently omitting all user scripts for new tabs,
+    // by nulling out shared_memory_, or only silently omitting new ones by
+    // leaving the existing object in place. The second seems less bad, even
+    // though it removes the possibility that freeing the shared memory block
+    // would open up enough FDs for long enough for a retry to succeed.
+
+    // Pretend the extension change didn't happen.
+    return;
+  }
+
+  // We've got scripts ready to go.
+  shared_memory_ = std::move(shared_memory);
+
+  for (content::RenderProcessHost::iterator i(
+           content::RenderProcessHost::AllHostsIterator());
+       !i.IsAtEnd(); i.Advance()) {
+    SendUpdate(i.GetCurrentValue(), shared_memory_);
+  }
+
+  // DCHECK(false); trying crash
+  prefs_->StartupTryout(0);
+
+  for (auto& observer : observers_)
+    observer.OnScriptsLoaded(this, browser_context_);
+}
+
+void UserScriptLoader::SendUpdate(
+    content::RenderProcessHost* process,
+    const base::ReadOnlySharedMemoryRegion& shared_memory) {
+  if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+    LOG(INFO) << "UserScriptLoader: SendUpdate";
+
+  // If the process is being started asynchronously, early return.  We'll end up
+  // calling InitUserScripts when it's created which will call this again.
+  base::ProcessHandle handle = process->GetProcess().Handle();
+  if (!handle)
+    return;
+
+  base::ReadOnlySharedMemoryRegion region_for_process =
+      shared_memory.Duplicate();
+  if (!region_for_process.IsValid())
+    return;
+
+  process->Send(new ExtensionMsg_UpdateUserScripts(
+     std::move(region_for_process)));
+}
+
+void LoadScriptsOnFileTaskRunner(
+    std::unique_ptr<UserScriptList> user_scripts,
+    UserScriptLoader::LoadScriptsCallback callback) {
+  DCHECK(GetUserScriptsFileTaskRunner()->RunsTasksInCurrentSequence());
+  DCHECK(user_scripts.get());
+
+  // load user scripts from path
+  LoadUserScripts(user_scripts.get());
+
+  base::ReadOnlySharedMemoryRegion memory;
+
+  // Explicit priority to prevent unwanted task priority inheritance.
+  content::GetUIThreadTaskRunner({base::TaskPriority::USER_BLOCKING})
+      ->PostTask(FROM_HERE,
+                 base::BindOnce(std::move(callback), std::move(user_scripts),
+                                std::move(memory)));
+}
+
+void UserScriptLoader::LoadScripts(
+    std::unique_ptr<UserScriptList> user_scripts,
+    LoadScriptsCallback callback) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  GetUserScriptsFileTaskRunner()->PostTask(
+      FROM_HERE,
+      base::BindOnce(&LoadScriptsOnFileTaskRunner, std::move(user_scripts),
+                     std::move(callback)));
+}
+
+void RemoveScriptsOnFileTaskRunner(
+    const std::string& script_id,
+    UserScriptLoader::RemoveScriptCallback callback) {
+  DCHECK(GetUserScriptsFileTaskRunner()->RunsTasksInCurrentSequence());
+
+  base::FilePath path;
+  if (GetOrCreatePath(path)) {
+    base::FilePath file = path.Append(script_id);
+    if( base::DeleteFile(file) == false ) {
+      LOG(ERROR) <<
+               "ERROR: failed to delete file : " << path;
+    }
+  }
+
+  content::GetUIThreadTaskRunner({base::TaskPriority::USER_BLOCKING})
+      ->PostTask(FROM_HERE,
+                 base::BindOnce(std::move(callback)));
+}
+
+void UserScriptLoader::OnScriptRemoved() {
+  StartLoad();
+}
+
+void UserScriptLoader::RemoveScript(const std::string& script_id) {
+  prefs_->RemoveScriptFromPrefs(script_id);
+
+  GetUserScriptsFileTaskRunner()->PostTask(
+      FROM_HERE,
+      base::BindOnce(&RemoveScriptsOnFileTaskRunner,
+                     std::move(script_id),
+                     base::BindOnce(&UserScriptLoader::OnScriptRemoved,
+                             weak_factory_.GetWeakPtr())));
+}
+
+void UserScriptLoader::SetScriptEnabled(const std::string& script_id, bool is_enabled) {
+  prefs_->SetScriptEnabled(script_id, is_enabled);
+  StartLoad();
+}
+
+void UserScriptLoader::SelectAndAddScriptFromFile(ui::WindowAndroid* nativeWindow) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  dialog_ = ui::SelectFileDialog::Create(
+      this, std::make_unique<ChromeSelectFilePolicy>(nullptr /*web_contents*/));
+
+  ui::SelectFileDialog::FileTypeInfo allowed_file_info;
+  allowed_file_info.extensions = {{FILE_PATH_LITERAL("js")}};
+  allowed_file_info.allowed_paths =
+      ui::SelectFileDialog::FileTypeInfo::ANY_PATH;
+  base::FilePath suggested_name;
+
+  std::vector<base::string16> types;
+  types.push_back(base::ASCIIToUTF16("*/*")); /*= java SelectFileDialog.ALL_TYPES*/
+  std::pair<std::vector<base::string16>, bool> accept_types = std::make_pair(
+      types, false /*use_media_capture*/);
+
+  dialog_->SelectFile(
+      ui::SelectFileDialog::SELECT_OPEN_FILE,
+      base::string16() /* dialog title*/, suggested_name, &allowed_file_info,
+      0 /* file type index */, std::string() /* default file extension */,
+      nativeWindow,
+      &accept_types /* params */);
+}
+
+
+void LoadScriptFromPathOnFileTaskRunner(
+  const base::FilePath& path,
+  const std::string& display_name,
+  UserScriptLoader::LoadSingleScriptCallback callback ) {
+  DCHECK(GetUserScriptsFileTaskRunner()->RunsTasksInCurrentSequence());
+
+  std::unique_ptr<UserScript> userscript(new UserScript());
+  base::string16 error;
+  bool result = LoadUserScriptFromFile(path, GURL(), userscript, &error);
+
+  if(result) {
+    if (display_name.empty() == false) {
+      userscript->set_key(display_name);
+    }
+
+    if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+      LOG(INFO) << "UserScriptLoader: Loaded " << userscript->name() <<
+                                    "-" << userscript->version() <<
+                                    "-" << userscript->description();
+    base::FilePath destination;
+    result = GetOrCreatePath(destination);
+    if( result == false ) {
+      error = base::ASCIIToUTF16("Cannot create destination.");
+    } else {
+      destination = destination.Append(userscript->key());
+      result = base::CopyFile(path, destination);
+      if (result == false) {
+        error = base::ASCIIToUTF16("Copy error.");
+      }
+    }
+  } else {
+    LOG(ERROR) << "UserScriptLoader: load error " << error;
+  }
+
+  const std::string string_error = base::UTF16ToASCII(error);
+
+  content::GetUIThreadTaskRunner({base::TaskPriority::USER_BLOCKING})
+      ->PostTask(FROM_HERE,
+                 base::BindOnce(std::move(callback), result,
+                                std::move(string_error)));
+}
+
+void UserScriptLoader::TryToInstall(const base::FilePath& script_path) {
+  base::string16 file_display_name;
+  base::MaybeGetFileDisplayName(script_path, &file_display_name);
+
+  std::string display_name = script_path.BaseName().value();
+  if (base::IsStringASCII(file_display_name))
+    display_name = base::UTF16ToASCII(file_display_name);
+
+  GetUserScriptsFileTaskRunner()->PostTask(
+      FROM_HERE,
+      base::BindOnce(
+        &LoadScriptFromPathOnFileTaskRunner,
+        script_path, display_name,
+        base::BindOnce(
+            &UserScriptLoader::LoadScriptFromPathOnFileTaskRunnerCallback,
+            weak_factory_.GetWeakPtr()
+        )
+      ));
+}
+
+void UserScriptLoader::FileSelected(
+    const base::FilePath& path, int index, void* params) {
+  if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+    LOG(INFO) << "UserScriptLoader: FileSelected " << path;
+
+  UserScriptLoader::TryToInstall(path);
+}
+
+void UserScriptLoader::LoadScriptFromPathOnFileTaskRunnerCallback(
+              bool result, const std::string& error) {
+  for (auto& observer : observers_)
+     observer.OnUserScriptLoaded(this, result, error);
+
+  StartLoad();
+}
+
+void UserScriptLoader::FileSelectionCanceled(
+    void* params) {
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/browser/user_script_loader.h b/components/user_scripts/browser/user_script_loader.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/browser/user_script_loader.h
@@ -0,0 +1,172 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef USERSCRIPTS_BROWSER_USER_SCRIPT_LOADER_H_
+#define USERSCRIPTS_BROWSER_USER_SCRIPT_LOADER_H_
+
+#include <map>
+#include <memory>
+#include <set>
+
+#include "base/callback_forward.h"
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "base/memory/read_only_shared_memory_region.h"
+#include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
+#include "base/scoped_observer.h"
+#include "content/public/browser/render_process_host_creation_observer.h"
+#include "ui/shell_dialogs/select_file_dialog.h"
+#include "content/browser/file_system_access/file_system_chooser.h"
+#include "ui/android/window_android.h"
+
+#include "../common/host_id.h"
+#include "../common/user_script.h"
+#include "user_script_prefs.h"
+
+namespace base {
+class ReadOnlySharedMemoryRegion;
+}
+
+namespace content {
+class BrowserContext;
+class RenderProcessHost;
+}
+
+namespace user_scripts {
+
+// Manages one "logical unit" of user scripts in shared memory by constructing a
+// new shared memory region when the set of scripts changes. Also notifies
+// renderers of new shared memory region when new renderers appear, or when
+// script reloading completes. Script loading lives on the file thread.
+class UserScriptLoader : public content::RenderProcessHostCreationObserver,
+                         public ui::SelectFileDialog::Listener {
+ public:
+  using LoadScriptsCallback =
+      base::OnceCallback<void(std::unique_ptr<UserScriptList>,
+                              base::ReadOnlySharedMemoryRegion shared_memory)>;
+  using LoadSingleScriptCallback =
+      base::OnceCallback<void(bool result, const std::string& error)>;
+
+  using RemoveScriptCallback =
+      base::OnceCallback<void()>;
+  class Observer {
+   public:
+    virtual void OnScriptsLoaded(UserScriptLoader* loader,
+                                 content::BrowserContext* browser_context) = 0;
+    virtual void OnUserScriptLoaderDestroyed(UserScriptLoader* loader) = 0;
+    virtual void OnUserScriptLoaded(UserScriptLoader* loader,
+                                bool result, const std::string& error) = 0;
+  };
+
+  // Parses the includes out of |script| and returns them in |includes|.
+  static bool ParseMetadataHeader(const base::StringPiece& script_text,
+                                  std::unique_ptr<UserScript>& script,
+                                  std::string& error_message);
+
+  UserScriptLoader(content::BrowserContext* browser_context,
+                   UserScriptsPrefs* prefs);
+                   //const HostID& host_id);
+  ~UserScriptLoader() override;
+
+  // Initiates procedure to start loading scripts on the file thread.
+  void StartLoad();
+
+  // Returns true if we have any scripts ready.
+  bool initial_load_complete() const { return shared_memory_.IsValid(); }
+
+  // Pickle user scripts and return pointer to the shared memory.
+  static base::ReadOnlySharedMemoryRegion Serialize(
+      const user_scripts::UserScriptList& scripts);
+
+  // Adds or removes observers.
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  // Sets the flag if the initial set of hosts has finished loading; if it's
+  // set to be true, calls AttempLoad() to bootstrap.
+  void SetReady(bool ready);
+
+  void RemoveScript(const std::string& script_id);
+  void SetScriptEnabled(const std::string& script_id, bool is_enabled);
+
+  void SelectAndAddScriptFromFile(ui::WindowAndroid* wa);
+  void TryToInstall(const base::FilePath& script_path);
+
+  void LoadScripts(std::unique_ptr<UserScriptList> user_scripts,
+                      LoadScriptsCallback callback);
+
+ protected:
+  content::BrowserContext* browser_context() const { return browser_context_; }
+
+  UserScriptsPrefs* prefs() const { return prefs_; }
+
+ private:
+  void OnRenderProcessHostCreated(
+      content::RenderProcessHost* process_host) override;
+
+  // Attempts to initiate a load.
+  void AttemptLoad();
+
+  // Called once we have finished loading the scripts on the file thread.
+  void OnScriptsLoaded(std::unique_ptr<UserScriptList> user_scripts,
+                       base::ReadOnlySharedMemoryRegion shared_memory);
+
+  // Sends the renderer process a new set of user scripts. If
+  // |changed_hosts| is not empty, this signals that only the scripts from
+  // those hosts should be updated. Otherwise, all hosts will be
+  // updated.
+  void SendUpdate(content::RenderProcessHost* process,
+                  const base::ReadOnlySharedMemoryRegion& shared_memory);
+
+  // Contains the scripts that were found the last time scripts were updated.
+  base::ReadOnlySharedMemoryRegion shared_memory_;
+
+  // List of scripts that are currently loaded. This is null when a load is in
+  // progress.
+  std::unique_ptr<UserScriptList> loaded_scripts_;
+
+  // If the initial set of hosts has finished loading.
+  bool ready_;
+
+  // The browser_context for which the scripts managed here are installed.
+  content::BrowserContext* browser_context_;
+
+  // Manage load and store from preferences
+  UserScriptsPrefs* prefs_;
+
+  // The associated observers.
+  base::ObserverList<Observer>::Unchecked observers_;
+
+  void OnScriptRemoved();
+
+  // Manage file dialog requests
+  scoped_refptr<ui::SelectFileDialog> dialog_;
+  void FileSelected(const base::FilePath& path,
+                    int index, void* params) override;
+  void FileSelectionCanceled(void* params) override;
+  void LoadScriptFromPathOnFileTaskRunnerCallback(
+                    bool result, const std::string& error );
+
+  base::WeakPtrFactory<UserScriptLoader> weak_factory_{this};
+
+  DISALLOW_COPY_AND_ASSIGN(UserScriptLoader);
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_BROWSER_USER_SCRIPT_LOADER_H_
diff --git a/components/user_scripts/browser/user_script_pref_info.cc b/components/user_scripts/browser/user_script_pref_info.cc
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/user_script_pref_info.cc
@@ -0,0 +1,34 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "user_script_pref_info.h"
+
+namespace user_scripts {
+
+UserScriptsListPrefs::ScriptInfo::ScriptInfo(const std::string& name,
+                                             const std::string& description,
+                                             const base::Time& install_time,
+                                             bool enabled)
+    : install_time(install_time),
+      enabled(enabled),
+      name_(name),
+      description_(description) {}
+
+UserScriptsListPrefs::ScriptInfo::ScriptInfo(const ScriptInfo& other) = default;
+UserScriptsListPrefs::ScriptInfo::~ScriptInfo() = default;
+
+}
\ No newline at end of file
diff --git a/components/user_scripts/browser/user_script_pref_info.h b/components/user_scripts/browser/user_script_pref_info.h
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/user_script_pref_info.h
@@ -0,0 +1,66 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef USERSCRIPTS_BROWSER_USERSCRIPT_PREF_INFO_H_
+#define USERSCRIPTS_BROWSER_USERSCRIPT_PREF_INFO_H_
+
+#include "base/values.h"
+#include "base/time/time.h"
+#include "components/keyed_service/core/keyed_service.h"
+
+namespace user_scripts {
+
+class UserScriptsListPrefs : public KeyedService {
+ public:
+  struct ScriptInfo {
+    ScriptInfo(const std::string& name,
+               const std::string& description,
+               const base::Time& install_time,
+               bool enabled);
+    ScriptInfo(const ScriptInfo& other);
+    ~ScriptInfo();
+
+    const std::string& name() const { return name_; }
+    void set_name(const std::string& name) { name_ = name; }
+
+    const std::string& description() const { return description_; }
+    void set_description(const std::string& description) { description_ = description; }
+
+    const std::string& version() const { return version_; }
+    void set_version(const std::string& version) { version_ = version; }
+
+    const std::string& file_path() const { return file_path_; }
+    void set_file_path(const std::string& file_path) { file_path_ = file_path; }
+
+    const std::string& url_source() const { return url_source_; }
+    void set_url_source(const std::string& url_source) { url_source_ = url_source; }
+
+    base::Time install_time;
+    bool enabled;
+
+  private:
+    std::string name_;
+    std::string description_;
+    std::string version_;
+    std::string file_path_;
+    std::string url_source_;
+  };
+};
+
+}
+
+#endif // USERSCRIPTS_BROWSER_USERSCRIPT_PREF_INFO_H_
\ No newline at end of file
diff --git a/components/user_scripts/browser/user_script_prefs.cc b/components/user_scripts/browser/user_script_prefs.cc
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/user_script_prefs.cc
@@ -0,0 +1,262 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <map>
+
+#include "base/values.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/json/json_writer.h"
+
+#include "chrome/browser/browser_process.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_manager.h"
+
+#include "components/prefs/pref_service.h"
+#include "components/prefs/scoped_user_pref_update.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+#include "user_script_prefs.h"
+#include "user_script_pref_info.h"
+#include "../common/user_script.h"
+#include "../common/user_scripts_features.h"
+
+namespace user_scripts {
+
+namespace {
+
+const char kUserScriptsEnabled[] = "userscripts.enabled";
+const char kUserScriptsStartup[] = "userscripts.startup";
+
+const char kUserScriptsList[] = "userscripts.scripts";
+const char kScriptIsEnabled[] = "enabled";
+const char kScriptName[] = "name";
+const char kScriptDescription[] = "description";
+const char kScriptVersion[] = "version";
+const char kScriptInstallTime[] = "install_time";
+const char kScriptFilePath[] = "file_path";
+const char kScriptUrlSource[] = "url_source";
+
+class PrefUpdate : public DictionaryPrefUpdate {
+ public:
+  PrefUpdate(PrefService* service,
+             const std::string& id,
+             const std::string& path)
+      : DictionaryPrefUpdate(service, path), id_(id) {}
+
+  ~PrefUpdate() override = default;
+
+  base::DictionaryValue* Get() override {
+    base::DictionaryValue* dict = DictionaryPrefUpdate::Get();
+    base::Value* dict_item =
+        dict->FindKeyOfType(id_, base::Value::Type::DICTIONARY);
+    if (!dict_item)
+      dict_item = dict->SetKey(id_, base::Value(base::Value::Type::DICTIONARY));
+    return static_cast<base::DictionaryValue*>(dict_item);
+  }
+
+ private:
+  const std::string id_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrefUpdate);
+};
+
+bool GetInt64FromPref(const base::DictionaryValue* dict,
+                      const std::string& key,
+                      int64_t* value) {
+  DCHECK(dict);
+  std::string value_str;
+  if (!dict->GetStringWithoutPathExpansion(key, &value_str)) {
+    VLOG(2) << "Can't find key in local pref dictionary. Invalid key: " << key
+            << ".";
+    return false;
+  }
+
+  if (!base::StringToInt64(value_str, value)) {
+    VLOG(2) << "Can't change string to int64_t. Invalid string value: "
+            << value_str << ".";
+    return false;
+  }
+
+  return true;
+}
+
+}
+
+UserScriptsPrefs::UserScriptsPrefs(
+    PrefService* prefs)
+    : prefs_(prefs) {
+}
+
+// static
+void UserScriptsPrefs::RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterBooleanPref(kUserScriptsEnabled, false);
+  registry->RegisterIntegerPref(kUserScriptsStartup, 0);
+  registry->RegisterDictionaryPref(kUserScriptsList);
+}
+
+bool UserScriptsPrefs::IsEnabled() {
+  return prefs_->GetBoolean(kUserScriptsEnabled);
+}
+
+void UserScriptsPrefs::SetEnabled(bool enabled) {
+  prefs_->SetBoolean(kUserScriptsEnabled, enabled);
+  prefs_->CommitPendingWrite();
+}
+
+void UserScriptsPrefs::StartupTryout(int number) {
+  prefs_->SetInteger(kUserScriptsStartup, number);
+  prefs_->CommitPendingWrite();
+}
+
+int UserScriptsPrefs::GetCurrentStartupTryout() {
+  return prefs_->GetInteger(kUserScriptsStartup);
+}
+
+void UserScriptsPrefs::CompareWithPrefs(UserScriptList& user_scripts) {
+  if( IsEnabled() == false ) {
+    if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+      LOG(INFO) << "UserScriptsPrefs: disabled by user";
+
+    user_scripts.clear();
+    return;
+  }
+
+  std::vector<std::string> all_scripts;
+
+  auto it = user_scripts.begin();
+  while (it != user_scripts.end())
+  {
+    std::string key = it->get()->key();
+    all_scripts.push_back(key);
+
+    std::unique_ptr<UserScriptsListPrefs::ScriptInfo> scriptInfo =
+        UserScriptsPrefs::CreateScriptInfoFromPrefs(key);
+
+    // add or update prefs
+    scriptInfo->set_name(it->get()->name());
+    scriptInfo->set_description(it->get()->description());
+    scriptInfo->set_version(it->get()->version());
+    scriptInfo->set_file_path(it->get()->file_path());
+    scriptInfo->set_url_source(it->get()->url_source());
+
+    PrefUpdate update(prefs_, key, kUserScriptsList);
+    base::DictionaryValue* script_dict = update.Get();
+
+    script_dict->SetString(kScriptName, scriptInfo->name());
+    script_dict->SetString(kScriptDescription, scriptInfo->description());
+    script_dict->SetBoolean(kScriptIsEnabled, scriptInfo->enabled);
+    script_dict->SetString(kScriptVersion, scriptInfo->version());
+    script_dict->SetString(kScriptFilePath, scriptInfo->file_path());
+    script_dict->SetString(kScriptUrlSource, scriptInfo->url_source());
+
+    std::string install_time_str =
+        base::NumberToString(scriptInfo->install_time.ToInternalValue());
+    script_dict->SetString(kScriptInstallTime, install_time_str);
+
+   if (!scriptInfo->enabled) {
+      it = user_scripts.erase(it);
+    } else {
+      ++it;
+    }
+  }
+
+  // remove script from prefs if no more present
+  std::vector<std::string> all_scripts_to_remove;
+  const base::DictionaryValue* dict =
+    prefs_->GetDictionary(kUserScriptsList);
+  for (base::DictionaryValue::Iterator script_it(*dict); !script_it.IsAtEnd();
+       script_it.Advance()) {
+    const std::string& key = script_it.key();
+
+    if (std::find(all_scripts.begin(), all_scripts.end(), key) == all_scripts.end()) {
+      all_scripts_to_remove.push_back(key);
+    }
+  }
+
+  DictionaryPrefUpdate update(prefs_, kUserScriptsList);
+  base::DictionaryValue* const update_dict = update.Get();
+  for (auto key : all_scripts_to_remove) {
+      update_dict->RemoveKey(key);
+  }
+
+  return;
+}
+
+std::string UserScriptsPrefs::GetScriptsInfo() {
+  std::string json_string;
+
+  const base::DictionaryValue* dict =
+    prefs_->GetDictionary(kUserScriptsList);
+
+  if (dict) {
+    base::JSONWriter::WriteWithOptions(
+        *dict, base::JSONWriter::OPTIONS_PRETTY_PRINT, &json_string);
+    base::TrimWhitespaceASCII(json_string, base::TRIM_ALL, &json_string);
+  }
+
+  return json_string;
+}
+
+std::unique_ptr<UserScriptsListPrefs::ScriptInfo> UserScriptsPrefs::CreateScriptInfoFromPrefs(
+    const std::string& script_id) const {
+
+  auto scriptInfo = std::make_unique<UserScriptsListPrefs::ScriptInfo>(
+      script_id, "", base::Time::Now(), false);
+
+  const base::DictionaryValue* scripts =
+      prefs_->GetDictionary(kUserScriptsList);
+  if (!scripts)
+    return scriptInfo;
+
+  const base::DictionaryValue* script = static_cast<const base::DictionaryValue*>(
+    scripts->FindDictKey(script_id));
+  if (!script)
+    return scriptInfo;
+
+  const std::string* name = script->FindStringKey(kScriptName);
+  const std::string* description = script->FindStringKey(kScriptDescription);
+  const std::string* version = script->FindStringKey(kScriptVersion);
+  const std::string* file_path = script->FindStringKey(kScriptFilePath);
+  const std::string* url_source = script->FindStringKey(kScriptUrlSource);
+
+  scriptInfo->set_name( name ? *name : "no name" );
+  scriptInfo->set_description( description ? *description : "no description" );
+  scriptInfo->set_version( version ? *version : "no version" );
+  scriptInfo->enabled = script->FindBoolKey(kScriptIsEnabled).value_or(false);
+  scriptInfo->set_file_path( file_path ? *file_path : "no file path" );
+  scriptInfo->set_url_source( url_source ? *url_source : "" );
+
+  int64_t time_interval = 0;
+  if (GetInt64FromPref(script, kScriptInstallTime, &time_interval)) {
+    scriptInfo->install_time = base::Time::FromInternalValue(time_interval);
+  }
+
+  return scriptInfo;
+}
+
+void UserScriptsPrefs::RemoveScriptFromPrefs(const std::string& script_id) {
+  DictionaryPrefUpdate update(prefs_, kUserScriptsList);
+  base::DictionaryValue* const update_dict = update.Get();
+  update_dict->RemoveKey(script_id);
+}
+
+void UserScriptsPrefs::SetScriptEnabled(const std::string& script_id, bool is_enabled) {
+  PrefUpdate update(prefs_, script_id, kUserScriptsList);
+  base::DictionaryValue* script_dict = update.Get();
+  script_dict->SetBoolean(kScriptIsEnabled, is_enabled);
+}
+
+}
diff --git a/components/user_scripts/browser/user_script_prefs.h b/components/user_scripts/browser/user_script_prefs.h
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/browser/user_script_prefs.h
@@ -0,0 +1,58 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef USERSCRIPTS_BROWSER_USERSCRIPT_PREFS_H_
+#define USERSCRIPTS_BROWSER_USERSCRIPT_PREFS_H_
+
+#include "content/public/browser/browser_context.h"
+#include "components/prefs/pref_service.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+
+#include "user_script_pref_info.h"
+#include "../common/user_script.h"
+
+namespace user_scripts {
+
+class UserScriptsPrefs {
+ public:
+    UserScriptsPrefs(
+        PrefService* prefs);
+
+    static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
+
+    bool IsEnabled();
+    void SetEnabled(bool enabled);
+
+    void StartupTryout(int number);
+    int GetCurrentStartupTryout();
+
+    void CompareWithPrefs(UserScriptList& user_scripts);
+
+    std::string GetScriptsInfo();
+    void RemoveScriptFromPrefs(const std::string& script_id);
+    void SetScriptEnabled(const std::string& script_id, bool is_enabled);
+
+    std::unique_ptr<UserScriptsListPrefs::ScriptInfo> CreateScriptInfoFromPrefs(
+        const std::string& script_id) const;
+
+ private:
+    PrefService* prefs_;
+};
+
+}
+
+#endif // USERSCRIPTS_BROWSER_USERSCRIPT_PREFS_H_
\ No newline at end of file
diff --git a/components/user_scripts/browser/userscripts_browser_client.cc b/components/user_scripts/browser/userscripts_browser_client.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/browser/userscripts_browser_client.cc
@@ -0,0 +1,79 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "userscripts_browser_client.h"
+
+#include "base/logging.h"
+
+#include "chrome/browser/browser_process.h"
+
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/profiles/profile_manager.h"
+
+#include "../common/user_scripts_features.h"
+#include "user_script_loader.h"
+#include "file_task_runner.h"
+#include "user_script_prefs.h"
+
+namespace user_scripts {
+
+namespace {
+
+// remember: was ExtensionsBrowserClient
+UserScriptsBrowserClient* g_userscripts_browser_client = NULL;
+
+}  // namespace
+
+UserScriptsBrowserClient::UserScriptsBrowserClient() {}
+
+UserScriptsBrowserClient::~UserScriptsBrowserClient() = default;
+
+// static
+UserScriptsBrowserClient* UserScriptsBrowserClient::GetInstance() {
+  // only for browser process
+  if(!g_browser_process)
+    return NULL;
+
+  if (base::FeatureList::IsEnabled(features::kEnableUserScripts) == false)
+    return NULL;
+
+  // singleton
+  if(g_userscripts_browser_client)
+    return g_userscripts_browser_client;
+
+  // make file task runner
+  GetUserScriptsFileTaskRunner().get();
+
+  // new instance singleton
+  g_userscripts_browser_client = new UserScriptsBrowserClient();
+
+  return g_userscripts_browser_client;
+}
+
+void UserScriptsBrowserClient::SetProfile(content::BrowserContext* context) {
+  browser_context_ = context;
+
+  prefs_ =
+    std::make_unique<user_scripts::UserScriptsPrefs>(
+      static_cast<Profile*>(context)->GetPrefs());
+
+  userscript_loader_ =
+    std::make_unique<user_scripts::UserScriptLoader>(browser_context_, prefs_.get());
+  userscript_loader_->SetReady(true);
+}
+
+}  // namespace user_scripts
diff --git a/components/user_scripts/browser/userscripts_browser_client.h b/components/user_scripts/browser/userscripts_browser_client.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/browser/userscripts_browser_client.h
@@ -0,0 +1,62 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef USERSCRIPTS_BROWSER_USERSCRIPTS_BROWSER_CLIENT_H_
+#define USERSCRIPTS_BROWSER_USERSCRIPTS_BROWSER_CLIENT_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "content/public/browser/browser_context.h"
+
+#include "../common/user_script.h"
+#include "user_script_loader.h"
+#include "user_script_prefs.h"
+
+namespace user_scripts {
+
+class UserScriptsBrowserClient {
+ public:
+  UserScriptsBrowserClient();
+  UserScriptsBrowserClient(const UserScriptsBrowserClient&) = delete;
+  UserScriptsBrowserClient& operator=(const UserScriptsBrowserClient&) = delete;
+  virtual ~UserScriptsBrowserClient();
+
+  // Returns the single instance of |this|.
+  static UserScriptsBrowserClient* GetInstance();
+
+  void SetProfile(content::BrowserContext* context);
+
+  user_scripts::UserScriptsPrefs* GetPrefs() {
+    return prefs_.get();
+  }
+
+  user_scripts::UserScriptLoader* GetLoader() {
+    return userscript_loader_.get();
+  }
+
+  private:
+    std::unique_ptr<UserScriptList> scripts_;
+    content::BrowserContext* browser_context_;
+    std::unique_ptr<user_scripts::UserScriptsPrefs> prefs_;
+    std::unique_ptr<user_scripts::UserScriptLoader> userscript_loader_;
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_BROWSER_USERSCRIPTS_BROWSER_CLIENT_H_
diff --git a/components/user_scripts/common/BUILD.gn b/components/user_scripts/common/BUILD.gn
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/BUILD.gn
@@ -0,0 +1,52 @@
+# Copyright 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/features.gni")
+import("//mojo/public/tools/bindings/mojom.gni")
+
+static_library("common") {
+  sources = [
+    "user_scripts_features.cc",
+    "user_scripts_features.h",
+    "constants.h",
+    "host_id.cc",
+    "host_id.h",
+    "script_constants.h",
+    "url_pattern_set.cc",
+    "url_pattern_set.h",
+    "url_pattern.cc",
+    "url_pattern.h",
+    "user_script.cc",
+    "user_script.h",
+    "view_type.cc",
+    "view_type.h",
+    "extension_messages.cc",
+    "extension_messages.h",
+    "extension_message_generator.cc",
+    "extension_message_generator.h",
+  ]
+
+  configs += [
+    "//build/config:precompiled_headers",
+
+    # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
+    "//build/config/compiler:no_size_t_to_int_warning",
+    "//build/config/compiler:wexit_time_destructors",
+  ]
+
+  public_deps = [
+    "//components/services/app_service/public/cpp:app_file_handling",
+    "//content/public/common",
+    "//ipc",
+    "//skia",
+  ]
+
+  deps = [
+    "//base",
+    "//components/url_formatter",
+    "//components/url_matcher",
+    "//components/version_info",
+    "//crypto",
+  ]
+}
diff --git a/components/user_scripts/common/constants.h b/components/user_scripts/common/constants.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/constants.h
@@ -0,0 +1,21 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_COMMON_CONSTANTS_H_
+#define USERSCRIPTS_COMMON_CONSTANTS_H_
+
+#include "base/files/file_path.h"
+#include "base/strings/string_piece_forward.h"
+#include "components/services/app_service/public/mojom/types.mojom.h"
+#include "components/version_info/channel.h"
+#include "ui/base/layout.h"
+
+namespace user_scripts {
+
+// The origin of injected CSS.
+enum CSSOrigin { /*CSS_ORIGIN_AUTHOR,*/ CSS_ORIGIN_USER };
+
+}  // namespace user_scripts
+
+#endif  // USERSCRIPTS_COMMON_CONSTANTS_H_
diff --git a/components/user_scripts/common/error_utils.cc b/components/user_scripts/common/error_utils.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/error_utils.cc
@@ -0,0 +1,54 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "error_utils.h"
+
+#include <initializer_list>
+
+#include "base/check_op.h"
+#include "base/strings/string_tokenizer.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+
+namespace user_scripts {
+
+namespace {
+
+std::string FormatErrorMessageInternal(
+    base::StringPiece format,
+    std::initializer_list<base::StringPiece> args) {
+  std::string format_str = format.as_string();
+  base::StringTokenizer tokenizer(format_str, "*");
+  tokenizer.set_options(base::StringTokenizer::RETURN_DELIMS);
+
+  std::vector<base::StringPiece> result_pieces;
+  auto* args_it = args.begin();
+  while (tokenizer.GetNext()) {
+    if (!tokenizer.token_is_delim()) {
+      result_pieces.push_back(tokenizer.token_piece());
+      continue;
+    }
+
+    CHECK_NE(args_it, args.end())
+        << "More placeholders (*) than substitutions.";
+
+    // Substitute the argument.
+    result_pieces.push_back(*args_it);
+    args_it++;
+  }
+
+  // Not all substitutions were consumed.
+  CHECK_EQ(args_it, args.end()) << "Fewer placeholders (*) than substitutions.";
+
+  return base::JoinString(result_pieces, "" /* separator */);
+}
+
+}  // namespace
+
+std::string ErrorUtils::FormatErrorMessage(base::StringPiece format,
+                                           base::StringPiece s1) {
+  return FormatErrorMessageInternal(format, {s1});
+}
+
+}  // namespace user_scripts
diff --git a/components/user_scripts/common/error_utils.h b/components/user_scripts/common/error_utils.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/error_utils.h
@@ -0,0 +1,25 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_COMMON_ERROR_UTILS_H_
+#define USERSCRIPTS_COMMON_ERROR_UTILS_H_
+
+#include <string>
+
+#include "base/strings/string16.h"
+#include "base/strings/string_piece.h"
+
+namespace user_scripts {
+
+class ErrorUtils {
+ public:
+   // Creates an error messages from a pattern.
+   static std::string FormatErrorMessage(base::StringPiece format,
+                                         base::StringPiece s1);
+
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_COMMON_ERROR_UTILS_H_
diff --git a/components/user_scripts/common/extension_message_generator.cc b/components/user_scripts/common/extension_message_generator.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/extension_message_generator.cc
@@ -0,0 +1,29 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Get basic type definitions.
+#define IPC_MESSAGE_IMPL
+#include "components/user_scripts/common/extension_message_generator.h"
+
+// Generate constructors.
+#include "ipc/struct_constructor_macros.h"
+#include "components/user_scripts/common/extension_message_generator.h"
+
+// Generate param traits write methods.
+#include "ipc/param_traits_write_macros.h"
+namespace IPC {
+#include "components/user_scripts/common/extension_message_generator.h"
+}  // namespace IPC
+
+// Generate param traits read methods.
+#include "ipc/param_traits_read_macros.h"
+namespace IPC {
+#include "components/user_scripts/common/extension_message_generator.h"
+}  // namespace IPC
+
+// Generate param traits log methods.
+#include "ipc/param_traits_log_macros.h"
+namespace IPC {
+#include "components/user_scripts/common/extension_message_generator.h"
+}  // namespace IPC
diff --git a/components/user_scripts/common/extension_message_generator.h b/components/user_scripts/common/extension_message_generator.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/extension_message_generator.h
@@ -0,0 +1,11 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Multiply-included file, hence no include guard.
+
+#undef EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
+#include "extension_messages.h"
+#ifndef EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
+#error "Failed to include header extension_messages.h"
+#endif
diff --git a/components/user_scripts/common/extension_messages.cc b/components/user_scripts/common/extension_messages.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/extension_messages.cc
@@ -0,0 +1,40 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "extension_messages.h"
+
+#include <stddef.h>
+
+#include <memory>
+#include <utility>
+
+#include "content/public/common/common_param_traits.h"
+
+namespace IPC {
+
+void ParamTraits<HostID>::Write(base::Pickle* m, const param_type& p) {
+  WriteParam(m, p.type());
+  WriteParam(m, p.id());
+}
+
+bool ParamTraits<HostID>::Read(const base::Pickle* m,
+                               base::PickleIterator* iter,
+                               param_type* r) {
+  HostID::HostType type;
+  std::string id;
+  if (!ReadParam(m, iter, &type))
+    return false;
+  if (!ReadParam(m, iter, &id))
+    return false;
+  *r = HostID(type, id);
+  return true;
+}
+
+void ParamTraits<HostID>::Log(
+    const param_type& p, std::string* l) {
+  LogParam(p.type(), l);
+  LogParam(p.id(), l);
+}
+
+}  // namespace IPC
diff --git a/components/user_scripts/common/extension_messages.h b/components/user_scripts/common/extension_messages.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/extension_messages.h
@@ -0,0 +1,70 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// IPC messages for extensions.
+
+#ifndef EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
+#define EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
+
+#include <stdint.h>
+
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/read_only_shared_memory_region.h"
+#include "base/values.h"
+#include "content/public/common/common_param_traits.h"
+#include "constants.h"
+#include "host_id.h"
+#include "ipc/ipc_message_macros.h"
+#include "url/gurl.h"
+#include "url/origin.h"
+
+#define IPC_MESSAGE_START ExtensionMsgStart
+
+IPC_ENUM_TRAITS_MAX_VALUE(HostID::HostType, HostID::HOST_TYPE_LAST)
+
+// Singly-included section for custom IPC traits.
+#ifndef INTERNAL_EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
+#define INTERNAL_EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
+
+namespace IPC {
+
+template <>
+struct ParamTraits<HostID> {
+  typedef HostID param_type;
+  static void Write(base::Pickle* m, const param_type& p);
+  static bool Read(const base::Pickle* m,
+                   base::PickleIterator* iter,
+                   param_type* r);
+  static void Log(const param_type& p, std::string* l);
+};
+
+
+}  // namespace IPC
+
+#endif  // INTERNAL_EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
+
+// Notification that the user scripts have been updated. It has one
+// ReadOnlySharedMemoryRegion argument consisting of the pickled script data.
+// This memory region is valid in the context of the renderer.
+// If |owner| is not empty, then the shared memory handle refers to |owner|'s
+// programmatically-defined scripts. Otherwise, the handle refers to all
+// hosts' statically defined scripts. So far, only extension-hosts support
+// statically defined scripts; WebUI-hosts don't.
+// If |changed_hosts| is not empty, only the host in that set will
+// be updated. Otherwise, all hosts that have scripts in the shared memory
+// region will be updated. Note that the empty set => all hosts case is not
+// supported for per-extension programmatically-defined script regions; in such
+// regions, the owner is expected to list itself as the only changed host.
+// If |whitelisted_only| is true, this process should only run whitelisted
+// scripts and not all user scripts.
+IPC_MESSAGE_CONTROL1(ExtensionMsg_UpdateUserScripts,
+                     base::ReadOnlySharedMemoryRegion)
+
+#endif  // EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
diff --git a/components/user_scripts/common/host_id.cc b/components/user_scripts/common/host_id.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/host_id.cc
@@ -0,0 +1,31 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "host_id.h"
+
+#include <tuple>
+
+HostID::HostID()
+    : type_(HostType::EXTENSIONS) {
+}
+
+HostID::HostID(HostType type, const std::string& id)
+    : type_(type), id_(id) {
+}
+
+HostID::HostID(const HostID& host_id)
+    : type_(host_id.type()),
+      id_(host_id.id()) {
+}
+
+HostID::~HostID() {
+}
+
+bool HostID::operator<(const HostID& host_id) const {
+  return std::tie(type_, id_) < std::tie(host_id.type_, host_id.id_);
+}
+
+bool HostID::operator==(const HostID& host_id) const {
+  return type_ == host_id.type_ && id_ == host_id.id_;
+}
diff --git a/components/user_scripts/common/host_id.h b/components/user_scripts/common/host_id.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/host_id.h
@@ -0,0 +1,35 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_COMMON_HOST_ID_H_
+#define USERSCRIPTS_COMMON_HOST_ID_H_
+
+#include <string>
+
+// IDs of hosts who own user scripts.
+// A HostID is immutable after creation.
+struct HostID {
+  enum HostType { EXTENSIONS, WEBUI, HOST_TYPE_LAST = WEBUI };
+
+  HostID();
+  HostID(HostType type, const std::string& id);
+  HostID(const HostID& host_id);
+  ~HostID();
+
+  bool operator<(const HostID& host_id) const;
+  bool operator==(const HostID& host_id) const;
+
+  HostType type() const { return type_; }
+  const std::string& id() const { return id_; }
+
+ private:
+  // The type of the host.
+  HostType type_;
+
+  // Similar to extension_id, host_id is a unique indentifier for a host,
+  // e.g., an Extension or WebUI.
+  std::string id_;
+};
+
+#endif  // USERSCRIPTS_COMMON_HOST_ID_H_
diff --git a/components/user_scripts/common/script_constants.h b/components/user_scripts/common/script_constants.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/script_constants.h
@@ -0,0 +1,33 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_COMMON_SCRIPT_CONSTANTS_H_
+#define USERSCRIPTS_COMMON_SCRIPT_CONSTANTS_H_
+
+namespace user_scripts {
+
+// Whether to fall back to matching the origin for frames where the URL
+// cannot be matched directly, such as those with about: or data: schemes.
+enum class MatchOriginAsFallbackBehavior {
+  // Never fall back on the origin; this means scripts will never match on
+  // these frames.
+  kNever,
+  // Match the origin only for about:-scheme frames, and then climb the frame
+  // tree to find an appropriate ancestor to get a full URL (including path).
+  // This is for supporting the "match_about_blank" key.
+  // TODO(devlin): I wonder if we could simplify this to be "MatchForAbout",
+  // and not worry about climbing the frame tree. It would be a behavior
+  // change, but I wonder how many extensions it would impact in practice.
+  kMatchForAboutSchemeAndClimbTree,
+  // Match the origin as a fallback whenever applicable. This won't have a
+  // corresponding path.
+  kAlways,
+};
+
+// TODO(devlin): Move the other non-UserScript-specific constants like
+// RunLocation and InjectionType from UserScript into here.
+
+}
+
+#endif  // USERSCRIPTS_COMMON_SCRIPT_CONSTANTS_H_
diff --git a/components/user_scripts/common/url_pattern.cc b/components/user_scripts/common/url_pattern.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/url_pattern.cc
@@ -0,0 +1,807 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "url_pattern.h"
+
+#include <stddef.h>
+
+#include <ostream>
+
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "base/strings/pattern.h"
+#include "base/strings/strcat.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "content/public/common/url_constants.h"
+#include "constants.h"
+#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+#include "net/base/url_util.h"
+#include "url/gurl.h"
+#include "url/url_util.h"
+
+const char URLPattern::kAllUrlsPattern[] = "<all_urls>";
+
+namespace {
+
+// TODO(aa): What about more obscure schemes like javascript: ?
+// Note: keep this array in sync with kValidSchemeMasks.
+const char* const kValidSchemes[] = {
+    url::kHttpScheme,         url::kHttpsScheme,
+    url::kFileScheme,         url::kFtpScheme,
+    /*content::kChromeUIScheme,*/ /*extensions::kExtensionScheme,*/
+    url::kFileSystemScheme,   url::kWsScheme,
+    url::kWssScheme,          url::kDataScheme,
+};
+
+const int kValidSchemeMasks[] = {
+    URLPattern::SCHEME_HTTP,       URLPattern::SCHEME_HTTPS,
+    URLPattern::SCHEME_FILE,       URLPattern::SCHEME_FTP,
+    /*URLPattern::SCHEME_CHROMEUI,*/   /*URLPattern::SCHEME_EXTENSION,*/
+    URLPattern::SCHEME_FILESYSTEM, URLPattern::SCHEME_WS,
+    URLPattern::SCHEME_WSS,        URLPattern::SCHEME_DATA,
+};
+
+static_assert(base::size(kValidSchemes) == base::size(kValidSchemeMasks),
+              "must keep these arrays in sync");
+
+const char kParseSuccess[] = "Success.";
+const char kParseErrorMissingSchemeSeparator[] = "Missing scheme separator.";
+const char kParseErrorInvalidScheme[] = "Invalid scheme.";
+const char kParseErrorWrongSchemeType[] = "Wrong scheme type.";
+const char kParseErrorEmptyHost[] = "Host can not be empty.";
+const char kParseErrorInvalidHostWildcard[] = "Invalid host wildcard.";
+const char kParseErrorEmptyPath[] = "Empty path.";
+const char kParseErrorInvalidPort[] = "Invalid port.";
+const char kParseErrorInvalidHost[] = "Invalid host.";
+
+// Message explaining each URLPattern::ParseResult.
+const char* const kParseResultMessages[] = {
+  kParseSuccess,
+  kParseErrorMissingSchemeSeparator,
+  kParseErrorInvalidScheme,
+  kParseErrorWrongSchemeType,
+  kParseErrorEmptyHost,
+  kParseErrorInvalidHostWildcard,
+  kParseErrorEmptyPath,
+  kParseErrorInvalidPort,
+  kParseErrorInvalidHost,
+};
+
+static_assert(static_cast<int>(URLPattern::ParseResult::kNumParseResults) ==
+                  base::size(kParseResultMessages),
+              "must add message for each parse result");
+
+const char kPathSeparator[] = "/";
+
+bool IsStandardScheme(base::StringPiece scheme) {
+  // "*" gets the same treatment as a standard scheme.
+  if (scheme == "*")
+    return true;
+
+  return url::IsStandard(scheme.data(),
+                         url::Component(0, static_cast<int>(scheme.length())));
+}
+
+bool IsValidPortForScheme(base::StringPiece scheme, base::StringPiece port) {
+  if (port == "*")
+    return true;
+
+  // Only accept non-wildcard ports if the scheme uses ports.
+  if (url::DefaultPortForScheme(scheme.data(), scheme.length()) ==
+      url::PORT_UNSPECIFIED) {
+    return false;
+  }
+
+  int parsed_port = url::PORT_UNSPECIFIED;
+  if (!base::StringToInt(port, &parsed_port))
+    return false;
+  return (parsed_port >= 0) && (parsed_port < 65536);
+}
+
+// Returns |path| with the trailing wildcard stripped if one existed.
+//
+// The functions that rely on this (OverlapsWith and Contains) are only
+// called for the patterns inside URLPatternSet. In those cases, we know that
+// the path will have only a single wildcard at the end. This makes figuring
+// out overlap much easier. It seems like there is probably a computer-sciency
+// way to solve the general case, but we don't need that yet.
+base::StringPiece StripTrailingWildcard(base::StringPiece path) {
+  if (base::EndsWith(path, "*"))
+    path.remove_suffix(1);
+  return path;
+}
+
+// Removes trailing dot from |host_piece| if any.
+base::StringPiece CanonicalizeHostForMatching(base::StringPiece host_piece) {
+  if (base::EndsWith(host_piece, "."))
+    host_piece.remove_suffix(1);
+  return host_piece;
+}
+
+}  // namespace
+
+// static
+bool URLPattern::IsValidSchemeForExtensions(base::StringPiece scheme) {
+  for (size_t i = 0; i < base::size(kValidSchemes); ++i) {
+    if (scheme == kValidSchemes[i])
+      return true;
+  }
+  return false;
+}
+
+// static
+int URLPattern::GetValidSchemeMaskForExtensions() {
+  int result = 0;
+  for (size_t i = 0; i < base::size(kValidSchemeMasks); ++i)
+    result |= kValidSchemeMasks[i];
+  return result;
+}
+
+URLPattern::URLPattern()
+    : valid_schemes_(SCHEME_NONE),
+      match_all_urls_(false),
+      match_subdomains_(false),
+      port_("*") {}
+
+URLPattern::URLPattern(int valid_schemes)
+    : valid_schemes_(valid_schemes),
+      match_all_urls_(false),
+      match_subdomains_(false),
+      port_("*") {}
+
+URLPattern::URLPattern(int valid_schemes, base::StringPiece pattern)
+    // Strict error checking is used, because this constructor is only
+    // appropriate when we know |pattern| is valid.
+    : valid_schemes_(valid_schemes),
+      match_all_urls_(false),
+      match_subdomains_(false),
+      port_("*") {
+  ParseResult result = Parse(pattern);
+  if (result != ParseResult::kSuccess) {
+    const char* error_string = GetParseResultString(result);
+    // Temporarily add more logging to investigate why this code path is
+    // reached. For http://crbug.com/856948
+    LOG(ERROR) << "Invalid pattern was given " << pattern << " result "
+               << error_string;
+    NOTREACHED() << "URLPattern invalid: '" << pattern
+                 << "'; error: " << error_string;
+  }
+}
+
+URLPattern::URLPattern(const URLPattern& other) = default;
+
+URLPattern::URLPattern(URLPattern&& other) = default;
+
+URLPattern::~URLPattern() {
+}
+
+URLPattern& URLPattern::operator=(const URLPattern& other) = default;
+
+URLPattern& URLPattern::operator=(URLPattern&& other) = default;
+
+bool URLPattern::operator<(const URLPattern& other) const {
+  return GetAsString() < other.GetAsString();
+}
+
+bool URLPattern::operator>(const URLPattern& other) const {
+  return GetAsString() > other.GetAsString();
+}
+
+bool URLPattern::operator==(const URLPattern& other) const {
+  return GetAsString() == other.GetAsString();
+}
+
+std::ostream& operator<<(std::ostream& out, const URLPattern& url_pattern) {
+  return out << '"' << url_pattern.GetAsString() << '"';
+}
+
+URLPattern::ParseResult URLPattern::Parse(base::StringPiece pattern) {
+  spec_.clear();
+  SetMatchAllURLs(false);
+  SetMatchSubdomains(false);
+  SetPort("*");
+
+  // Special case pattern to match every valid URL.
+  if (pattern == kAllUrlsPattern) {
+    SetMatchAllURLs(true);
+    return ParseResult::kSuccess;
+  }
+
+  // Parse out the scheme.
+  size_t scheme_end_pos = pattern.find(url::kStandardSchemeSeparator);
+  bool has_standard_scheme_separator = true;
+
+  // Some urls also use ':' alone as the scheme separator.
+  if (scheme_end_pos == base::StringPiece::npos) {
+    scheme_end_pos = pattern.find(':');
+    has_standard_scheme_separator = false;
+  }
+
+  if (scheme_end_pos == base::StringPiece::npos)
+    return ParseResult::kMissingSchemeSeparator;
+
+  if (!SetScheme(pattern.substr(0, scheme_end_pos)))
+    return ParseResult::kInvalidScheme;
+
+  bool standard_scheme = IsStandardScheme(scheme_);
+  if (standard_scheme != has_standard_scheme_separator)
+    return ParseResult::kWrongSchemeSeparator;
+
+  // Advance past the scheme separator.
+  scheme_end_pos +=
+      (standard_scheme ? strlen(url::kStandardSchemeSeparator) : 1);
+  if (scheme_end_pos >= pattern.size())
+    return ParseResult::kEmptyHost;
+
+  // Parse out the host and path.
+  size_t host_start_pos = scheme_end_pos;
+  size_t path_start_pos = 0;
+
+  if (!standard_scheme) {
+    path_start_pos = host_start_pos;
+  } else if (scheme_ == url::kFileScheme) {
+    size_t host_end_pos = pattern.find(kPathSeparator, host_start_pos);
+    if (host_end_pos == base::StringPiece::npos) {
+      // Allow hostname omission.
+      // e.g. file://* is interpreted as file:///*,
+      // file://foo* is interpreted as file:///foo*.
+      path_start_pos = host_start_pos - 1;
+    } else {
+      // Ignore hostname if scheme is file://.
+      // e.g. file://localhost/foo is equal to file:///foo.
+      path_start_pos = host_end_pos;
+    }
+  } else {
+    size_t host_end_pos = pattern.find(kPathSeparator, host_start_pos);
+
+    // Host is required.
+    if (host_start_pos == host_end_pos)
+      return ParseResult::kEmptyHost;
+
+    if (host_end_pos == base::StringPiece::npos)
+      return ParseResult::kEmptyPath;
+
+    base::StringPiece host_and_port =
+        pattern.substr(host_start_pos, host_end_pos - host_start_pos);
+
+    size_t port_separator_pos = base::StringPiece::npos;
+    if (host_and_port[0] != '[') {
+      // Not IPv6 (either IPv4 or just a normal address).
+      port_separator_pos = host_and_port.find(':');
+    } else {  // IPv6.
+      size_t host_end_pos = host_and_port.find(']');
+      if (host_end_pos == base::StringPiece::npos)
+        return ParseResult::kInvalidHost;
+      if (host_end_pos == 1)
+        return ParseResult::kEmptyHost;
+
+      if (host_end_pos < host_and_port.length() - 1) {
+        // The host isn't the only component. Check for a port. This would
+        // require a ':' to follow the closing ']' from the host.
+        if (host_and_port[host_end_pos + 1] != ':')
+          return ParseResult::kInvalidHost;
+
+        port_separator_pos = host_end_pos + 1;
+      }
+    }
+
+    if (port_separator_pos != base::StringPiece::npos &&
+        !SetPort(host_and_port.substr(port_separator_pos + 1))) {
+      return ParseResult::kInvalidPort;
+    }
+
+    // Note: this substr() will be the entire string if the port position
+    // wasn't found.
+    base::StringPiece host_piece = host_and_port.substr(0, port_separator_pos);
+
+    if (host_piece.empty())
+      return ParseResult::kEmptyHost;
+
+    if (host_piece == "*") {
+      match_subdomains_ = true;
+      host_piece = base::StringPiece();
+    } else if (base::StartsWith(host_piece, "*.")) {
+      if (host_piece.length() == 2) {
+        // We don't allow just '*.' as a host.
+        return ParseResult::kEmptyHost;
+      }
+      match_subdomains_ = true;
+      host_piece = host_piece.substr(2);
+    }
+
+    host_ = host_piece.as_string();
+
+    path_start_pos = host_end_pos;
+  }
+
+  SetPath(pattern.substr(path_start_pos));
+
+  // No other '*' can occur in the host, though. This isn't necessary, but is
+  // done as a convenience to developers who might otherwise be confused and
+  // think '*' works as a glob in the host.
+  if (host_.find('*') != std::string::npos)
+    return ParseResult::kInvalidHostWildcard;
+
+  if (!host_.empty()) {
+    // If |host_| is present (i.e., isn't a wildcard), we need to canonicalize
+    // it.
+    url::CanonHostInfo host_info;
+    host_ = net::CanonicalizeHost(host_, &host_info);
+    // net::CanonicalizeHost() returns an empty string on failure.
+    if (host_.empty())
+      return ParseResult::kInvalidHost;
+  }
+
+  // Null characters are not allowed in hosts.
+  if (host_.find('\0') != std::string::npos)
+    return ParseResult::kInvalidHost;
+
+  return ParseResult::kSuccess;
+}
+
+void URLPattern::SetValidSchemes(int valid_schemes) {
+  // TODO(devlin): Should we check that valid_schemes agrees with |scheme_|
+  // here? Otherwise, valid_schemes_ and schemes_ may stop agreeing with each
+  // other (e.g., in the case of `*://*/*`, where the scheme should only be
+  // http or https).
+  spec_.clear();
+  valid_schemes_ = valid_schemes;
+}
+
+void URLPattern::SetHost(base::StringPiece host) {
+  spec_.clear();
+  host_.assign(host.data(), host.size());
+}
+
+void URLPattern::SetMatchAllURLs(bool val) {
+  spec_.clear();
+  match_all_urls_ = val;
+
+  if (val) {
+    match_subdomains_ = true;
+    scheme_ = "*";
+    host_.clear();
+    SetPath("/*");
+  }
+}
+
+void URLPattern::SetMatchSubdomains(bool val) {
+  spec_.clear();
+  match_subdomains_ = val;
+}
+
+bool URLPattern::SetScheme(base::StringPiece scheme) {
+  spec_.clear();
+  scheme_.assign(scheme.data(), scheme.size());
+  if (scheme_ == "*") {
+    valid_schemes_ &= (SCHEME_HTTP | SCHEME_HTTPS);
+  } else if (!IsValidScheme(scheme_)) {
+    return false;
+  }
+  return true;
+}
+
+bool URLPattern::IsValidScheme(base::StringPiece scheme) const {
+  if (valid_schemes_ == SCHEME_ALL)
+    return true;
+
+  for (size_t i = 0; i < base::size(kValidSchemes); ++i) {
+    if (scheme == kValidSchemes[i] && (valid_schemes_ & kValidSchemeMasks[i]))
+      return true;
+  }
+
+  return false;
+}
+
+void URLPattern::SetPath(base::StringPiece path) {
+  spec_.clear();
+  path_.assign(path.data(), path.size());
+  path_escaped_ = path_;
+  base::ReplaceSubstringsAfterOffset(&path_escaped_, 0, "\\", "\\\\");
+  base::ReplaceSubstringsAfterOffset(&path_escaped_, 0, "?", "\\?");
+}
+
+bool URLPattern::SetPort(base::StringPiece port) {
+  spec_.clear();
+  if (IsValidPortForScheme(scheme_, port)) {
+    port_.assign(port.data(), port.size());
+    return true;
+  }
+  return false;
+}
+
+bool URLPattern::MatchesURL(const GURL& test) const {
+  // Invalid URLs can never match.
+  if (!test.is_valid())
+    return false;
+
+  const GURL* test_url = &test;
+  bool has_inner_url = test.inner_url() != nullptr;
+
+  if (has_inner_url) {
+    if (!test.SchemeIsFileSystem())
+      return false;  // The only nested URLs we handle are filesystem URLs.
+    test_url = test.inner_url();
+  }
+
+  // Ensure the scheme matches first, since <all_urls> may not match this URL if
+  // the scheme is excluded.
+  if (!MatchesScheme(test_url->scheme_piece()))
+    return false;
+
+  if (match_all_urls_)
+    return true;
+
+  // Unless |match_all_urls_| is true, the grammar only permits matching
+  // URLs with nonempty paths.
+  if (!test.has_path())
+    return false;
+
+  std::string path_for_request = test.PathForRequest();
+  if (has_inner_url) {
+    path_for_request = base::StringPrintf("%s%s", test_url->path_piece().data(),
+                                          path_for_request.c_str());
+  }
+
+  return MatchesSecurityOriginHelper(*test_url) &&
+         MatchesPath(path_for_request);
+}
+
+bool URLPattern::MatchesSecurityOrigin(const GURL& test) const {
+  const GURL* test_url = &test;
+  bool has_inner_url = test.inner_url() != NULL;
+
+  if (has_inner_url) {
+    if (!test.SchemeIsFileSystem())
+      return false;  // The only nested URLs we handle are filesystem URLs.
+    test_url = test.inner_url();
+  }
+
+  if (!MatchesScheme(test_url->scheme()))
+    return false;
+
+  if (match_all_urls_)
+    return true;
+
+  return MatchesSecurityOriginHelper(*test_url);
+}
+
+bool URLPattern::MatchesScheme(base::StringPiece test) const {
+  if (!IsValidScheme(test))
+    return false;
+
+  return scheme_ == "*" || test == scheme_;
+}
+
+bool URLPattern::MatchesHost(base::StringPiece host) const {
+  // TODO(devlin): This is a bit sad. Parsing urls is expensive. However, it's
+  // important that we do this conversion to a GURL in order to canonicalize the
+  // host (the pattern's host_ already is canonicalized from Parse()). We can't
+  // just do string comparison.
+  return MatchesHost(
+      GURL(base::StringPrintf("%s%s%s/", url::kHttpScheme,
+                              url::kStandardSchemeSeparator, host.data())));
+}
+
+bool URLPattern::MatchesHost(const GURL& test) const {
+  base::StringPiece test_host(CanonicalizeHostForMatching(test.host_piece()));
+  const base::StringPiece pattern_host(CanonicalizeHostForMatching(host_));
+
+  // If the hosts are exactly equal, we have a match.
+  if (test_host == pattern_host)
+    return true;
+
+  // If we're matching subdomains, and we have no host in the match pattern,
+  // that means that we're matching all hosts, which means we have a match no
+  // matter what the test host is.
+  if (match_subdomains_ && pattern_host.empty())
+    return true;
+
+  // Otherwise, we can only match if our match pattern matches subdomains.
+  if (!match_subdomains_)
+    return false;
+
+  // We don't do subdomain matching against IP addresses, so we can give up now
+  // if the test host is an IP address.
+  if (test.HostIsIPAddress())
+    return false;
+
+  // Check if the test host is a subdomain of our host.
+  if (test_host.length() <= (pattern_host.length() + 1))
+    return false;
+
+  if (!base::EndsWith(test_host, pattern_host))
+    return false;
+
+  return test_host[test_host.length() - pattern_host.length() - 1] == '.';
+}
+
+bool URLPattern::MatchesEffectiveTld(
+    net::registry_controlled_domains::PrivateRegistryFilter private_filter,
+    net::registry_controlled_domains::UnknownRegistryFilter unknown_filter)
+    const {
+  // Check if it matches all urls or is a pattern like http://*/*.
+  if (match_all_urls_ || (match_subdomains_ && host_.empty()))
+    return true;
+
+  // If this doesn't even match subdomains, it can't possibly be a TLD wildcard.
+  if (!match_subdomains_)
+    return false;
+
+  // If there was more than just a TLD in the host (e.g., *.foobar.com), it
+  // doesn't match all hosts in an effective TLD.
+  if (net::registry_controlled_domains::HostHasRegistryControlledDomain(
+          host_, unknown_filter, private_filter)) {
+    return false;
+  }
+
+  // At this point the host could either be just a TLD ("com") or some unknown
+  // TLD-like string ("notatld"). To disambiguate between them construct a
+  // fake URL, and check the registry.
+  //
+  // If we recognized this TLD, then this is a pattern like *.com, and it
+  // matches an effective TLD.
+  return net::registry_controlled_domains::HostHasRegistryControlledDomain(
+      "notatld." + host_, unknown_filter, private_filter);
+}
+
+bool URLPattern::MatchesSingleOrigin() const {
+  // Strictly speaking, the port is part of the origin, but in URLPattern it
+  // defaults to *. It's not very interesting anyway, so leave it out.
+  return !MatchesEffectiveTld() && scheme_ != "*" && !match_subdomains_;
+}
+
+bool URLPattern::MatchesPath(base::StringPiece test) const {
+  // Make the behaviour of OverlapsWith consistent with MatchesURL, which is
+  // need to match hosted apps on e.g. 'google.com' also run on 'google.com/'.
+  // The below if is a no-copy way of doing (test + "/*" == path_escaped_).
+  if (path_escaped_.length() == test.length() + 2 &&
+      base::StartsWith(path_escaped_.c_str(), test) &&
+      base::EndsWith(path_escaped_, "/*")) {
+    return true;
+  }
+
+  return base::MatchPattern(test, path_escaped_);
+}
+
+const std::string& URLPattern::GetAsString() const {
+  if (!spec_.empty())
+    return spec_;
+
+  if (match_all_urls_) {
+    spec_ = kAllUrlsPattern;
+    return spec_;
+  }
+
+  bool standard_scheme = IsStandardScheme(scheme_);
+
+  std::string spec = scheme_ +
+      (standard_scheme ? url::kStandardSchemeSeparator : ":");
+
+  if (scheme_ != url::kFileScheme && standard_scheme) {
+    if (match_subdomains_) {
+      spec += "*";
+      if (!host_.empty())
+        spec += ".";
+    }
+
+    if (!host_.empty())
+      spec += host_;
+
+    if (port_ != "*") {
+      spec += ":";
+      spec += port_;
+    }
+  }
+
+  if (!path_.empty())
+    spec += path_;
+
+  spec_ = std::move(spec);
+  return spec_;
+}
+
+bool URLPattern::OverlapsWith(const URLPattern& other) const {
+  if (match_all_urls() || other.match_all_urls())
+    return true;
+  return (MatchesAnyScheme(other.GetExplicitSchemes()) ||
+          other.MatchesAnyScheme(GetExplicitSchemes()))
+      && (MatchesHost(other.host()) || other.MatchesHost(host()))
+      && (MatchesPortPattern(other.port()) || other.MatchesPortPattern(port()))
+      && (MatchesPath(StripTrailingWildcard(other.path())) ||
+          other.MatchesPath(StripTrailingWildcard(path())));
+}
+
+bool URLPattern::Contains(const URLPattern& other) const {
+  // Important: it's not enough to just check match_all_urls(); we also need to
+  // make sure that the schemes in this pattern are a superset of those in
+  // |other|.
+  if (match_all_urls() &&
+      (valid_schemes_ & other.valid_schemes_) == other.valid_schemes_) {
+    return true;
+  }
+
+  return MatchesAllSchemes(other.GetExplicitSchemes()) &&
+         MatchesHost(other.host()) &&
+         (!other.match_subdomains_ || match_subdomains_) &&
+         MatchesPortPattern(other.port()) &&
+         MatchesPath(StripTrailingWildcard(other.path()));
+}
+
+base::Optional<URLPattern> URLPattern::CreateIntersection(
+    const URLPattern& other) const {
+  // Easy case: Schemes don't overlap. Return nullopt.
+  int intersection_schemes = URLPattern::SCHEME_NONE;
+  if (valid_schemes_ == URLPattern::SCHEME_ALL)
+    intersection_schemes = other.valid_schemes_;
+  else if (other.valid_schemes_ == URLPattern::SCHEME_ALL)
+    intersection_schemes = valid_schemes_;
+  else
+    intersection_schemes = valid_schemes_ & other.valid_schemes_;
+
+  if (intersection_schemes == URLPattern::SCHEME_NONE)
+    return base::nullopt;
+
+  {
+    // In a few cases, we can (mostly) return a copy of one of the patterns.
+    // This can happen when either:
+    // - The URLPattern's are identical (possibly excluding valid_schemes_)
+    // - One of the patterns has match_all_urls() equal to true.
+    // NOTE(devlin): Theoretically, we could use Contains() instead of
+    // match_all_urls() here. However, Contains() strips the trailing wildcard
+    // from the path, which could yield the incorrect result.
+    const URLPattern* copy_source = nullptr;
+    if (*this == other || other.match_all_urls())
+      copy_source = this;
+    else if (match_all_urls())
+      copy_source = &other;
+
+    if (copy_source) {
+      // NOTE: equality checks don't take into account valid_schemes_, and
+      // schemes can be different in the case of match_all_urls() as well, so
+      // we can't always just return *copy_source.
+      if (intersection_schemes == copy_source->valid_schemes_)
+        return *copy_source;
+      URLPattern result(intersection_schemes);
+      ParseResult parse_result = result.Parse(copy_source->GetAsString());
+      CHECK_EQ(ParseResult::kSuccess, parse_result);
+      return result;
+    }
+  }
+
+  // No more easy cases. Go through component by component to find the patterns
+  // that intersect.
+
+  // Note: Alias the function type (rather than using auto) because
+  // MatchesHost() is overloaded.
+  using match_function_type = bool (URLPattern::*)(base::StringPiece) const;
+
+  auto get_intersection = [this, &other](base::StringPiece own_str,
+                                         base::StringPiece other_str,
+                                         match_function_type match_function,
+                                         base::StringPiece* out) {
+    if ((this->*match_function)(other_str)) {
+      *out = other_str;
+      return true;
+    }
+    if ((other.*match_function)(own_str)) {
+      *out = own_str;
+      return true;
+    }
+    return false;
+  };
+
+  base::StringPiece scheme;
+  base::StringPiece host;
+  base::StringPiece port;
+  base::StringPiece path;
+  // If any pieces fail to overlap, then there is no intersection.
+  if (!get_intersection(scheme_, other.scheme_, &URLPattern::MatchesScheme,
+                        &scheme) ||
+      !get_intersection(host_, other.host_, &URLPattern::MatchesHost, &host) ||
+      !get_intersection(port_, other.port_, &URLPattern::MatchesPortPattern,
+                        &port) ||
+      !get_intersection(path_, other.path_, &URLPattern::MatchesPath, &path)) {
+    return base::nullopt;
+  }
+
+  // Only match subdomains if both patterns match subdomains.
+  base::StringPiece subdomains;
+  if (match_subdomains_ && other.match_subdomains_) {
+    // The host may be empty (e.g., in the case of *://*/* - in that case, only
+    // append '*' instead of '*.'.
+    subdomains = host.empty() ? "*" : "*.";
+  }
+
+  base::StringPiece scheme_separator =
+      IsStandardScheme(scheme) ? url::kStandardSchemeSeparator : ":";
+
+  std::string pattern_str = base::StrCat(
+      {scheme, scheme_separator, subdomains, host, ":", port, path});
+
+  URLPattern pattern(intersection_schemes);
+  ParseResult result = pattern.Parse(pattern_str);
+  // TODO(devlin): I don't think there's any way this should ever fail, but
+  // use a CHECK() to flush any cases out. If nothing crops up, downgrade this
+  // to a DCHECK in M72.
+  CHECK_EQ(ParseResult::kSuccess, result);
+
+  return pattern;
+}
+
+bool URLPattern::MatchesAnyScheme(
+    const std::vector<std::string>& schemes) const {
+  for (auto i = schemes.cbegin(); i != schemes.cend(); ++i) {
+    if (MatchesScheme(*i))
+      return true;
+  }
+
+  return false;
+}
+
+bool URLPattern::MatchesAllSchemes(
+    const std::vector<std::string>& schemes) const {
+  for (auto i = schemes.cbegin(); i != schemes.cend(); ++i) {
+    if (!MatchesScheme(*i))
+      return false;
+  }
+
+  return true;
+}
+
+bool URLPattern::MatchesSecurityOriginHelper(const GURL& test) const {
+  // Ignore hostname if scheme is file://.
+  if (scheme_ != url::kFileScheme && !MatchesHost(test))
+    return false;
+
+  if (!MatchesPortPattern(base::NumberToString(test.EffectiveIntPort())))
+    return false;
+
+  return true;
+}
+
+bool URLPattern::MatchesPortPattern(base::StringPiece port) const {
+  return port_ == "*" || port_ == port;
+}
+
+std::vector<std::string> URLPattern::GetExplicitSchemes() const {
+  std::vector<std::string> result;
+
+  if (scheme_ != "*" && !match_all_urls_ && IsValidScheme(scheme_)) {
+    result.push_back(scheme_);
+    return result;
+  }
+
+  for (size_t i = 0; i < base::size(kValidSchemes); ++i) {
+    if (MatchesScheme(kValidSchemes[i])) {
+      result.push_back(kValidSchemes[i]);
+    }
+  }
+
+  return result;
+}
+
+std::vector<URLPattern> URLPattern::ConvertToExplicitSchemes() const {
+  std::vector<std::string> explicit_schemes = GetExplicitSchemes();
+  std::vector<URLPattern> result;
+
+  for (std::vector<std::string>::const_iterator i = explicit_schemes.begin();
+       i != explicit_schemes.end(); ++i) {
+    URLPattern temp = *this;
+    temp.SetScheme(*i);
+    temp.SetMatchAllURLs(false);
+    result.push_back(temp);
+  }
+
+  return result;
+}
+
+// static
+const char* URLPattern::GetParseResultString(
+    URLPattern::ParseResult parse_result) {
+  return kParseResultMessages[static_cast<int>(parse_result)];
+}
diff --git a/components/user_scripts/common/url_pattern.h b/components/user_scripts/common/url_pattern.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/url_pattern.h
@@ -0,0 +1,301 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#ifndef USERSCRIPTS_COMMON_URL_PATTERN_H_
+#define USERSCRIPTS_COMMON_URL_PATTERN_H_
+
+#include <functional>
+#include <iosfwd>
+#include <string>
+#include <vector>
+
+#include "base/strings/string_piece.h"
+#include "net/base/registry_controlled_domains/registry_controlled_domain.h"
+
+class GURL;
+
+// A pattern that can be used to match URLs. A URLPattern is a very restricted
+// subset of URL syntax:
+//
+// <url-pattern> := <scheme>://<host><port><path> | '<all_urls>'
+// <scheme> := '*' | 'http' | 'https' | 'file' | 'ftp' | 'chrome' |
+//             'chrome-extension' | 'filesystem'
+// <host> := '*' | <IPv4 address> | [<IPv6 address>] |
+//           '*.' <anychar except '/' and '*'>+
+// <port> := [':' ('*' | <port number between 0 and 65535>)]
+// <path> := '/' <any chars>
+//
+// * Host is not used when the scheme is 'file'.
+// * The path can have embedded '*' characters which act as glob wildcards.
+// * '<all_urls>' is a special pattern that matches any valid URL that contains
+//   a valid scheme (as specified by valid_schemes_).
+// * The '*' scheme pattern excludes file URLs.
+//
+// Examples of valid patterns:
+// - http://*/*
+// - http://*/foo*
+// - https://*.google.com/foo*bar
+// - file://monkey*
+// - http://127.0.0.1/*
+// - http://[2607:f8b0:4005:805::200e]/*
+//
+// Examples of invalid patterns:
+// - http://* -- path not specified
+// - http://*foo/bar -- * not allowed as substring of host component
+// - http://foo.*.bar/baz -- * must be first component
+// - http:/bar -- scheme separator not found
+// - foo://* -- invalid scheme
+// - chrome:// -- we don't support chrome internal URLs
+class URLPattern {
+ public:
+  // A collection of scheme bitmasks for use with valid_schemes.
+  enum SchemeMasks {
+    SCHEME_NONE = 0,
+    SCHEME_HTTP = 1 << 0,
+    SCHEME_HTTPS = 1 << 1,
+    SCHEME_FILE = 1 << 2,
+    SCHEME_FTP = 1 << 3,
+    SCHEME_CHROMEUI = 1 << 4,
+    SCHEME_EXTENSION = 1 << 5,
+    SCHEME_FILESYSTEM = 1 << 6,
+    SCHEME_WS = 1 << 7,
+    SCHEME_WSS = 1 << 8,
+    SCHEME_DATA = 1 << 9,
+
+    // IMPORTANT!
+    // SCHEME_ALL will match every scheme, including chrome://, chrome-
+    // extension://, about:, etc. Because this has lots of security
+    // implications, third-party extensions should usually not be able to get
+    // access to URL patterns initialized this way. If there is a reason
+    // for violating this general rule, document why this it safe.
+    SCHEME_ALL = -1,
+  };
+
+  // Error codes returned from Parse().
+  enum class ParseResult {
+    kSuccess = 0,
+    kMissingSchemeSeparator,
+    kInvalidScheme,
+    kWrongSchemeSeparator,
+    kEmptyHost,
+    kInvalidHostWildcard,
+    kEmptyPath,
+    kInvalidPort,
+    kInvalidHost,
+    kNumParseResults,
+  };
+
+  // The <all_urls> string pattern.
+  static const char kAllUrlsPattern[];
+
+  // Returns true if the given |scheme| is considered valid for extensions.
+  static bool IsValidSchemeForExtensions(base::StringPiece scheme);
+
+  // Returns the mask for all schemes considered valid for extensions.
+  static int GetValidSchemeMaskForExtensions();
+
+  explicit URLPattern(int valid_schemes);
+
+  // Convenience to construct a URLPattern from a string. If the string is not
+  // known ahead of time, use Parse() instead, which returns success or failure.
+  URLPattern(int valid_schemes, base::StringPiece pattern);
+
+  URLPattern();
+  URLPattern(const URLPattern& other);
+  URLPattern(URLPattern&& other);
+  ~URLPattern();
+
+  URLPattern& operator=(const URLPattern& other);
+  URLPattern& operator=(URLPattern&& other);
+
+  bool operator<(const URLPattern& other) const;
+  bool operator>(const URLPattern& other) const;
+  bool operator==(const URLPattern& other) const;
+
+  // Initializes this instance by parsing the provided string. Returns
+  // URLPattern::ParseResult::kSuccess on success, or an error code otherwise.
+  // On failure, this instance will have some intermediate values and is in an
+  // invalid state.
+  ParseResult Parse(base::StringPiece pattern_str);
+
+  // Gets the bitmask of valid schemes.
+  int valid_schemes() const { return valid_schemes_; }
+  void SetValidSchemes(int valid_schemes);
+
+  // Gets the host the pattern matches. This can be an empty string if the
+  // pattern matches all hosts (the input was <scheme>://*/<whatever>).
+  const std::string& host() const { return host_; }
+  void SetHost(base::StringPiece host);
+
+  // Gets whether to match subdomains of host().
+  bool match_subdomains() const { return match_subdomains_; }
+  void SetMatchSubdomains(bool val);
+
+  // Gets the path the pattern matches with the leading slash. This can have
+  // embedded asterisks which are interpreted using glob rules.
+  const std::string& path() const { return path_; }
+  void SetPath(base::StringPiece path);
+
+  // Returns true if this pattern matches all (valid) urls.
+  bool match_all_urls() const { return match_all_urls_; }
+  void SetMatchAllURLs(bool val);
+
+  // Sets the scheme for pattern matches. This can be a single '*' if the
+  // pattern matches all valid schemes (as defined by the valid_schemes_
+  // property). Returns false on failure (if the scheme is not valid).
+  bool SetScheme(base::StringPiece scheme);
+  // Note: You should use MatchesScheme() instead of this getter unless you
+  // absolutely need the exact scheme. This is exposed for testing.
+  const std::string& scheme() const { return scheme_; }
+
+  // Returns true if the specified scheme can be used in this URL pattern, and
+  // false otherwise. Uses valid_schemes_ to determine validity.
+  bool IsValidScheme(base::StringPiece scheme) const;
+
+  // Returns true if this instance matches the specified URL. Always returns
+  // false for invalid URLs.
+  bool MatchesURL(const GURL& test) const;
+
+  // Returns true if this instance matches the specified security origin.
+  bool MatchesSecurityOrigin(const GURL& test) const;
+
+  // Returns true if |test| matches our scheme.
+  // Note that if test is "filesystem", this may fail whereas MatchesURL
+  // may succeed.  MatchesURL is smart enough to look at the inner_url instead
+  // of the outer "filesystem:" part.
+  bool MatchesScheme(base::StringPiece test) const;
+
+  // Returns true if |test| matches our host.
+  bool MatchesHost(base::StringPiece test) const;
+  bool MatchesHost(const GURL& test) const;
+
+  // Returns true if |test| matches our path.
+  bool MatchesPath(base::StringPiece test) const;
+
+  // Returns true if the pattern matches all patterns in an (e)TLD. This
+  // includes patterns like *://*.com/*, *://*.co.uk/*, etc. A pattern that
+  // matches all domains (e.g., *://*/*) will return true.
+  // |private_filter| specifies whether private registries (like appspot.com)
+  // should be considered; if included, patterns like *://*.appspot.com/* will
+  // return true. By default, we exclude private registries (so *.appspot.com
+  // returns false).
+  // Note: This is an expensive method, and should be used sparingly!
+  // You should probably use URLPatternSet::ShouldWarnAllHosts(), which is
+  // cached.
+  bool MatchesEffectiveTld(
+      net::registry_controlled_domains::PrivateRegistryFilter private_filter =
+          net::registry_controlled_domains::EXCLUDE_PRIVATE_REGISTRIES,
+      net::registry_controlled_domains::UnknownRegistryFilter unknown_filter =
+          net::registry_controlled_domains::EXCLUDE_UNKNOWN_REGISTRIES) const;
+
+  // Returns true if the pattern only matches a single origin. The pattern may
+  // include a path.
+  bool MatchesSingleOrigin() const;
+
+  // Sets the port. Returns false if the port is invalid.
+  bool SetPort(base::StringPiece port);
+  const std::string& port() const { return port_; }
+
+  // Returns a string representing this instance.
+  const std::string& GetAsString() const;
+
+  // Determines whether there is a URL that would match this instance and
+  // another instance. This method is symmetrical: Calling
+  // other.OverlapsWith(this) would result in the same answer.
+  bool OverlapsWith(const URLPattern& other) const;
+
+  // Returns true if this pattern matches all possible URLs that |other| can
+  // match. For example, http://*.google.com encompasses http://www.google.com.
+  bool Contains(const URLPattern& other) const;
+
+  // Creates a new URLPattern that represents the intersection of this
+  // URLPattern with the |other|, or base::nullopt if no intersection exists.
+  // For instance, given the patterns http://*.google.com/* and
+  // *://maps.google.com/*, the intersection is http://maps.google.com/*.
+  // NOTES:
+  // - Though scheme intersections are supported, the serialization of
+  //   URLPatternSet does not record them. Be sure that this is safe for your
+  //   use cases.
+  // - Path intersection is done on a best-effort basis. If one path clearly
+  //   contains another, it will be handled correctly, but this method does not
+  //   deal with cases like /*a* and /*b* (where technically the intersection
+  //   is /*a*b*|/*b*a*); the intersection returned for that case will be empty.
+  base::Optional<URLPattern> CreateIntersection(const URLPattern& other) const;
+
+  // Converts this URLPattern into an equivalent set of URLPatterns that don't
+  // use a wildcard in the scheme component. If this URLPattern doesn't use a
+  // wildcard scheme, then the returned set will contain one element that is
+  // equivalent to this instance.
+  std::vector<URLPattern> ConvertToExplicitSchemes() const;
+
+  static bool EffectiveHostCompare(const URLPattern& a, const URLPattern& b) {
+    if (a.match_all_urls_ && b.match_all_urls_)
+      return false;
+    return a.host_.compare(b.host_) < 0;
+  }
+
+  // Used for origin comparisons in a std::set.
+  class EffectiveHostCompareFunctor {
+   public:
+    bool operator()(const URLPattern& a, const URLPattern& b) const {
+      return EffectiveHostCompare(a, b);
+    }
+  };
+
+  // Get an error string for a ParseResult.
+  static const char* GetParseResultString(URLPattern::ParseResult parse_result);
+
+ private:
+  // Returns true if any of the |schemes| items matches our scheme.
+  bool MatchesAnyScheme(const std::vector<std::string>& schemes) const;
+
+  // Returns true if all of the |schemes| items matches our scheme.
+  bool MatchesAllSchemes(const std::vector<std::string>& schemes) const;
+
+  bool MatchesSecurityOriginHelper(const GURL& test) const;
+
+  // Returns true if our port matches the |port| pattern (it may be "*").
+  bool MatchesPortPattern(base::StringPiece port) const;
+
+  // If the URLPattern contains a wildcard scheme, returns a list of
+  // equivalent literal schemes, otherwise returns the current scheme.
+  std::vector<std::string> GetExplicitSchemes() const;
+
+  // A bitmask containing the schemes which are considered valid for this
+  // pattern. Parse() uses this to decide whether a pattern contains a valid
+  // scheme.
+  int valid_schemes_;
+
+  // True if this is a special-case "<all_urls>" pattern.
+  bool match_all_urls_;
+
+  // The scheme for the pattern.
+  std::string scheme_;
+
+  // The host without any leading "*" components.
+  std::string host_;
+
+  // Whether we should match subdomains of the host. This is true if the first
+  // component of the pattern's host was "*".
+  bool match_subdomains_;
+
+  // The port.
+  std::string port_;
+
+  // The path to match. This is everything after the host of the URL, or
+  // everything after the scheme in the case of file:// URLs.
+  std::string path_;
+
+  // The path with "?" and "\" characters escaped for use with the
+  // MatchPattern() function.
+  std::string path_escaped_;
+
+  // A string representing this URLPattern.
+  mutable std::string spec_;
+};
+
+std::ostream& operator<<(std::ostream& out, const URLPattern& url_pattern);
+
+typedef std::vector<URLPattern> URLPatternList;
+
+#endif  // USERSCRIPTS_COMMON_URL_PATTERN_H_
diff --git a/components/user_scripts/common/url_pattern_set.cc b/components/user_scripts/common/url_pattern_set.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/url_pattern_set.cc
@@ -0,0 +1,330 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "url_pattern_set.h"
+
+#include <iterator>
+#include <ostream>
+
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "base/values.h"
+#include "error_utils.h"
+#include "url_pattern.h"
+#include "url/gurl.h"
+#include "url/origin.h"
+#include "url/url_constants.h"
+#include "user_scripts_features.h"
+
+namespace user_scripts {
+
+namespace {
+
+const char kInvalidURLPatternError[] = "Invalid url pattern '*'";
+
+}  // namespace
+
+// static
+URLPatternSet URLPatternSet::CreateDifference(const URLPatternSet& set1,
+                                              const URLPatternSet& set2) {
+  return URLPatternSet(base::STLSetDifference<std::set<URLPattern>>(
+      set1.patterns_, set2.patterns_));
+}
+
+// static
+URLPatternSet URLPatternSet::CreateIntersection(
+    const URLPatternSet& set1,
+    const URLPatternSet& set2,
+    IntersectionBehavior intersection_behavior) {
+  // Note: leverage return value optimization; always return the same object.
+  URLPatternSet result;
+
+  if (intersection_behavior == IntersectionBehavior::kStringComparison) {
+    // String comparison just relies on STL set behavior, which looks at the
+    // string representation.
+    result = URLPatternSet(base::STLSetIntersection<std::set<URLPattern>>(
+        set1.patterns_, set2.patterns_));
+    return result;
+  }
+
+  // Look for a semantic intersection.
+
+  // Step 1: Iterate over each set. Find any patterns that are completely
+  // contained by the other (thus being necessarily present in any intersection)
+  // and add them, collecting the others in a set of unique items.
+  // Note: Use a collection of pointers for the uniques to avoid excessive
+  // copies. Since these are owned by the URLPatternSet passed in, which is
+  // const, this should be safe.
+  std::vector<const URLPattern*> unique_set1;
+  for (const URLPattern& pattern : set1) {
+    if (set2.ContainsPattern(pattern))
+      result.patterns_.insert(pattern);
+    else
+      unique_set1.push_back(&pattern);
+  }
+  std::vector<const URLPattern*> unique_set2;
+  for (const URLPattern& pattern : set2) {
+    if (set1.ContainsPattern(pattern))
+      result.patterns_.insert(pattern);
+    else
+      unique_set2.push_back(&pattern);
+  }
+
+  // If we're just looking for patterns contained by both, we're done.
+  if (intersection_behavior == IntersectionBehavior::kPatternsContainedByBoth)
+    return result;
+
+  DCHECK_EQ(IntersectionBehavior::kDetailed, intersection_behavior);
+
+  // Step 2: Iterate over all the unique patterns and find the intersections
+  // they have with the other patterns.
+  for (const auto* pattern : unique_set1) {
+    for (const auto* pattern2 : unique_set2) {
+      base::Optional<URLPattern> intersection =
+          pattern->CreateIntersection(*pattern2);
+      if (intersection)
+        result.patterns_.insert(std::move(*intersection));
+    }
+  }
+
+  return result;
+}
+
+// static
+URLPatternSet URLPatternSet::CreateUnion(const URLPatternSet& set1,
+                                         const URLPatternSet& set2) {
+  return URLPatternSet(
+      base::STLSetUnion<std::set<URLPattern>>(set1.patterns_, set2.patterns_));
+}
+
+// static
+URLPatternSet URLPatternSet::CreateUnion(
+    const std::vector<URLPatternSet>& sets) {
+  URLPatternSet result;
+  if (sets.empty())
+    return result;
+
+  // N-way union algorithm is basic O(nlog(n)) merge algorithm.
+  //
+  // Do the first merge step into a working set so that we don't mutate any of
+  // the input.
+  // TODO(devlin): Looks like this creates a bunch of copies; we can probably
+  // clean that up.
+  std::vector<URLPatternSet> working;
+  for (size_t i = 0; i < sets.size(); i += 2) {
+    if (i + 1 < sets.size())
+      working.push_back(CreateUnion(sets[i], sets[i + 1]));
+    else
+      working.push_back(sets[i].Clone());
+  }
+
+  for (size_t skip = 1; skip < working.size(); skip *= 2) {
+    for (size_t i = 0; i < (working.size() - skip); i += skip) {
+      URLPatternSet u = CreateUnion(working[i], working[i + skip]);
+      working[i].patterns_.swap(u.patterns_);
+    }
+  }
+
+  result.patterns_.swap(working[0].patterns_);
+  return result;
+}
+
+URLPatternSet::URLPatternSet() = default;
+
+URLPatternSet::URLPatternSet(URLPatternSet&& rhs) = default;
+
+URLPatternSet::URLPatternSet(const std::set<URLPattern>& patterns)
+    : patterns_(patterns) {}
+
+URLPatternSet::~URLPatternSet() = default;
+
+URLPatternSet& URLPatternSet::operator=(URLPatternSet&& rhs) = default;
+
+bool URLPatternSet::operator==(const URLPatternSet& other) const {
+  return patterns_ == other.patterns_;
+}
+
+std::ostream& operator<<(std::ostream& out,
+                         const URLPatternSet& url_pattern_set) {
+  out << "{ ";
+
+  auto iter = url_pattern_set.patterns().cbegin();
+  if (!url_pattern_set.patterns().empty()) {
+    out << *iter;
+    ++iter;
+  }
+
+  for (;iter != url_pattern_set.patterns().end(); ++iter)
+    out << ", " << *iter;
+
+  if (!url_pattern_set.patterns().empty())
+    out << " ";
+
+  out << "}";
+  return out;
+}
+
+URLPatternSet URLPatternSet::Clone() const {
+  return URLPatternSet(patterns_);
+}
+
+bool URLPatternSet::is_empty() const {
+  return patterns_.empty();
+}
+
+size_t URLPatternSet::size() const {
+  return patterns_.size();
+}
+
+bool URLPatternSet::AddPattern(const URLPattern& pattern) {
+  return patterns_.insert(pattern).second;
+}
+
+void URLPatternSet::AddPatterns(const URLPatternSet& set) {
+  patterns_.insert(set.patterns().begin(),
+                   set.patterns().end());
+}
+
+void URLPatternSet::ClearPatterns() {
+  patterns_.clear();
+}
+
+bool URLPatternSet::AddOrigin(int valid_schemes, const GURL& origin) {
+  if (origin.is_empty())
+    return false;
+  const url::Origin real_origin = url::Origin::Create(origin);
+  DCHECK(real_origin.IsSameOriginWith(url::Origin::Create(origin.GetOrigin())));
+  URLPattern origin_pattern(valid_schemes);
+  // Origin adding could fail if |origin| does not match |valid_schemes|.
+  if (origin_pattern.Parse(origin.spec()) !=
+      URLPattern::ParseResult::kSuccess) {
+    return false;
+  }
+  origin_pattern.SetPath("/*");
+  return AddPattern(origin_pattern);
+}
+
+bool URLPatternSet::Contains(const URLPatternSet& other) const {
+  for (auto it = other.begin(); it != other.end(); ++it) {
+    if (!ContainsPattern(*it))
+      return false;
+  }
+
+  return true;
+}
+
+bool URLPatternSet::ContainsPattern(const URLPattern& pattern) const {
+  for (auto it = begin(); it != end(); ++it) {
+    if (it->Contains(pattern))
+      return true;
+  }
+  return false;
+}
+
+bool URLPatternSet::MatchesURL(const GURL& url) const {
+  for (auto pattern = patterns_.cbegin(); pattern != patterns_.cend();
+       ++pattern) {
+    if (pattern->MatchesURL(url)) {
+      if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+        LOG(INFO) << "UserScripts: URLPatternSet::MatchesURL true " << url.spec();
+
+      return true;
+    }
+  }
+
+  if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+    LOG(INFO) << "UserScripts: URLPatternSet::MatchesURL false " << url.spec();
+
+  return false;
+}
+
+bool URLPatternSet::MatchesAllURLs() const {
+  for (auto host = begin(); host != end(); ++host) {
+    if (host->match_all_urls() ||
+        (host->match_subdomains() && host->host().empty()))
+      return true;
+  }
+  return false;
+}
+
+bool URLPatternSet::MatchesSecurityOrigin(const GURL& origin) const {
+  for (auto pattern = patterns_.begin(); pattern != patterns_.end();
+       ++pattern) {
+    if (pattern->MatchesSecurityOrigin(origin))
+      return true;
+  }
+
+  return false;
+}
+
+bool URLPatternSet::OverlapsWith(const URLPatternSet& other) const {
+  // Two extension extents overlap if there is any one URL that would match at
+  // least one pattern in each of the extents.
+  for (auto i = patterns_.cbegin(); i != patterns_.cend(); ++i) {
+    for (auto j = other.patterns().cbegin(); j != other.patterns().cend();
+         ++j) {
+      if (i->OverlapsWith(*j))
+        return true;
+    }
+  }
+
+  return false;
+}
+
+std::unique_ptr<base::ListValue> URLPatternSet::ToValue() const {
+  std::unique_ptr<base::ListValue> value(new base::ListValue);
+  for (auto i = patterns_.cbegin(); i != patterns_.cend(); ++i)
+    value->AppendIfNotPresent(std::make_unique<base::Value>(i->GetAsString()));
+  return value;
+}
+
+bool URLPatternSet::Populate(const std::vector<std::string>& patterns,
+                             int valid_schemes,
+                             bool allow_file_access,
+                             std::string* error) {
+  ClearPatterns();
+  for (size_t i = 0; i < patterns.size(); ++i) {
+    URLPattern pattern(valid_schemes);
+    if (pattern.Parse(patterns[i]) != URLPattern::ParseResult::kSuccess) {
+      if (error) {
+        *error = ErrorUtils::FormatErrorMessage(kInvalidURLPatternError,
+                                                patterns[i]);
+      } else {
+        LOG(ERROR) << "Invalid url pattern: " << patterns[i];
+      }
+      return false;
+    }
+    if (!allow_file_access && pattern.MatchesScheme(url::kFileScheme)) {
+      pattern.SetValidSchemes(
+          pattern.valid_schemes() & ~URLPattern::SCHEME_FILE);
+    }
+    AddPattern(pattern);
+  }
+  return true;
+}
+
+std::unique_ptr<std::vector<std::string>> URLPatternSet::ToStringVector()
+    const {
+  std::unique_ptr<std::vector<std::string>> value(new std::vector<std::string>);
+  for (auto i = patterns_.cbegin(); i != patterns_.cend(); ++i) {
+    value->push_back(i->GetAsString());
+  }
+  return value;
+}
+
+bool URLPatternSet::Populate(const base::ListValue& value,
+                             int valid_schemes,
+                             bool allow_file_access,
+                             std::string* error) {
+  std::vector<std::string> patterns;
+  for (size_t i = 0; i < value.GetSize(); ++i) {
+    std::string item;
+    if (!value.GetString(i, &item))
+      return false;
+    patterns.push_back(item);
+  }
+  return Populate(patterns, valid_schemes, allow_file_access, error);
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/common/url_pattern_set.h b/components/user_scripts/common/url_pattern_set.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/url_pattern_set.h
@@ -0,0 +1,161 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_COMMON_URL_PATTERN_SET_H_
+#define USERSCRIPTS_COMMON_URL_PATTERN_SET_H_
+
+#include <stddef.h>
+
+#include <iosfwd>
+#include <memory>
+#include <set>
+
+#include "base/macros.h"
+#include "url_pattern.h"
+
+class GURL;
+
+namespace base {
+class ListValue;
+class Value;
+}
+
+namespace user_scripts {
+
+// Represents the set of URLs an extension uses for web content.
+class URLPatternSet {
+ public:
+  typedef std::set<URLPattern>::const_iterator const_iterator;
+  typedef std::set<URLPattern>::iterator iterator;
+
+  // Returns |set1| - |set2|.
+  static URLPatternSet CreateDifference(const URLPatternSet& set1,
+                                        const URLPatternSet& set2);
+
+  enum class IntersectionBehavior {
+    // For the following descriptions, consider the two URLPatternSets:
+    // Set 1: {"https://example.com/*", "https://*.google.com/*", "http://*/*"}
+    // Set 2: {"https://example.com/*", "https://google.com/maps",
+    //         "*://chromium.org/*"}
+
+    // Only includes patterns that are exactly in both sets. The intersection of
+    // the two sets above is {"https://example.com/*"}, since that is the only
+    // pattern that appears exactly in each.
+    kStringComparison,
+
+    // Includes patterns that are effectively contained by both sets. The
+    // intersection of the two sets above is
+    // {
+    //   "https://example.com/*" (contained exactly by each set)
+    //   "https://google.com/maps" (contained exactly by set 2 and a strict
+    //                              subset of https://*.google.com/* in set 1)
+    // }
+    kPatternsContainedByBoth,
+
+    // Includes patterns that are contained by both sets and creates new
+    // patterns to represent the intersection of any others. The intersection of
+    // the two sets above is
+    // {
+    //   "https://example.com/*" (contained exactly by each set)
+    //   "https://google.com/maps" (contained exactly by set 2 and a strict
+    //                              subset of https://*.google.com/* in set 1)
+    //   "http://chromium.org/*" (the overlap between "http://*/*" in set 1 and
+    //                            *://chromium.org/*" in set 2).
+    // }
+    // Note that this is the most computationally expensive - potentially
+    // O(n^2) - since it can require comparing each pattern in one set to every
+    // pattern in the other set.
+    kDetailed,
+  };
+
+  // Returns the intersection of |set1| and |set2| according to
+  // |intersection_behavior|.
+  static URLPatternSet CreateIntersection(
+      const URLPatternSet& set1,
+      const URLPatternSet& set2,
+      IntersectionBehavior intersection_behavior);
+
+  // Returns the union of |set1| and |set2|.
+  static URLPatternSet CreateUnion(const URLPatternSet& set1,
+                                   const URLPatternSet& set2);
+
+  // Returns the union of all sets in |sets|.
+  static URLPatternSet CreateUnion(const std::vector<URLPatternSet>& sets);
+
+  URLPatternSet();
+  URLPatternSet(URLPatternSet&& rhs);
+  explicit URLPatternSet(const std::set<URLPattern>& patterns);
+  ~URLPatternSet();
+
+  URLPatternSet& operator=(URLPatternSet&& rhs);
+  bool operator==(const URLPatternSet& rhs) const;
+
+  bool is_empty() const;
+  size_t size() const;
+  const std::set<URLPattern>& patterns() const { return patterns_; }
+  const_iterator begin() const { return patterns_.begin(); }
+  const_iterator end() const { return patterns_.end(); }
+  iterator erase(iterator iter) { return patterns_.erase(iter); }
+
+  // Returns a copy of this URLPatternSet; not instrumented as a copy
+  // constructor to avoid accidental/unnecessary copies.
+  URLPatternSet Clone() const;
+
+  // Adds a pattern to the set. Returns true if a new pattern was inserted,
+  // false if the pattern was already in the set.
+  bool AddPattern(const URLPattern& pattern);
+
+  // Adds all patterns from |set| into this.
+  void AddPatterns(const URLPatternSet& set);
+
+  void ClearPatterns();
+
+  // Adds a pattern based on |origin| to the set.
+  bool AddOrigin(int valid_schemes, const GURL& origin);
+
+  // Returns true if every URL that matches |set| is matched by this. In other
+  // words, if every pattern in |set| is encompassed by a pattern in this.
+  bool Contains(const URLPatternSet& set) const;
+
+  // Returns true if any pattern in this set encompasses |pattern|.
+  bool ContainsPattern(const URLPattern& pattern) const;
+
+  // Test if the extent contains a URL.
+  bool MatchesURL(const GURL& url) const;
+
+  // Test if the extent matches all URLs (for example, <all_urls>).
+  bool MatchesAllURLs() const;
+
+  bool MatchesSecurityOrigin(const GURL& origin) const;
+
+  // Returns true if there is a single URL that would be in two extents.
+  bool OverlapsWith(const URLPatternSet& other) const;
+
+  // Converts to and from Value for serialization to preferences.
+  std::unique_ptr<base::ListValue> ToValue() const;
+  bool Populate(const base::ListValue& value,
+                int valid_schemes,
+                bool allow_file_access,
+                std::string* error);
+
+  // Converts to and from a vector of strings.
+  std::unique_ptr<std::vector<std::string>> ToStringVector() const;
+  bool Populate(const std::vector<std::string>& patterns,
+                int valid_schemes,
+                bool allow_file_access,
+                std::string* error);
+
+ private:
+  // The list of URL patterns that comprise the extent.
+  std::set<URLPattern> patterns_;
+
+  DISALLOW_COPY_AND_ASSIGN(URLPatternSet);
+};
+
+std::ostream& operator<<(std::ostream& out,
+                         const URLPatternSet& url_pattern_set);
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_COMMON_URL_PATTERN_SET_H_
diff --git a/components/user_scripts/common/user_script.cc b/components/user_scripts/common/user_script.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/user_script.cc
@@ -0,0 +1,317 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "user_script.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <memory>
+#include <utility>
+
+#include "base/atomic_sequence_num.h"
+#include "base/command_line.h"
+#include "base/pickle.h"
+#include "base/strings/pattern.h"
+#include "base/strings/string_util.h"
+#include "user_scripts_features.h"
+
+namespace {
+
+// This cannot be a plain int or int64_t because we need to generate unique IDs
+// from multiple threads.
+base::AtomicSequenceNumber g_user_script_id_generator;
+
+bool UrlMatchesGlobs(const std::vector<std::string>* globs,
+                     const GURL& url) {
+  for (auto glob = globs->cbegin(); glob != globs->cend(); ++glob) {
+    if (base::MatchPattern(url.spec(), *glob))
+      return true;
+  }
+
+  return false;
+}
+
+}  // namespace
+
+namespace user_scripts {
+
+// The bitmask for valid user script injectable schemes used by URLPattern.
+enum {
+  kValidUserScriptSchemes = //URLPattern::SCHEME_CHROMEUI |
+                            URLPattern::SCHEME_HTTP |
+                            URLPattern::SCHEME_HTTPS
+                            //| URLPattern::SCHEME_FILE |
+                            //URLPattern::SCHEME_FTP
+};
+
+// static
+const char UserScript::kFileExtension[] = ".user.js";
+
+// static
+int UserScript::GenerateUserScriptID() {
+  return g_user_script_id_generator.GetNext();
+}
+
+bool UserScript::IsURLUserScript(const GURL& url,
+                                 const std::string& mime_type) {
+  return base::EndsWith(url.ExtractFileName(), kFileExtension,
+                        base::CompareCase::INSENSITIVE_ASCII) &&
+         mime_type != "text/html";
+}
+
+// static
+int UserScript::ValidUserScriptSchemes(bool canExecuteScriptEverywhere) {
+  if (canExecuteScriptEverywhere)
+    return URLPattern::SCHEME_ALL;
+  int valid_schemes = kValidUserScriptSchemes;
+  // if (!base::CommandLine::ForCurrentProcess()->HasSwitch(
+  //         switches::kExtensionsOnChromeURLs)) {
+  //   valid_schemes &= ~URLPattern::SCHEME_CHROMEUI;
+  // }
+  return valid_schemes;
+}
+
+UserScript::File::File(const base::FilePath& extension_root,
+                       const base::FilePath& relative_path,
+                       const GURL& url)
+    : extension_root_(extension_root),
+      relative_path_(relative_path),
+      url_(url) {
+}
+
+UserScript::File::File() {}
+
+UserScript::File::File(const File& other)
+    : extension_root_(other.extension_root_),
+      relative_path_(other.relative_path_),
+      url_(other.url_),
+      external_content_(other.external_content_),
+      content_(other.content_),
+      key_(other.key_) {}
+
+UserScript::File::~File() {}
+
+UserScript::UserScript() = default;
+UserScript::~UserScript() = default;
+
+void UserScript::add_url_pattern(const URLPattern& pattern) {
+  url_set_.AddPattern(pattern);
+}
+
+void UserScript::add_exclude_url_pattern(const URLPattern& pattern) {
+  exclude_url_set_.AddPattern(pattern);
+}
+
+bool UserScript::MatchesURL(const GURL& url) const {
+  if (!url_set_.is_empty()) {
+    if (!url_set_.MatchesURL(url)) {
+      if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+        LOG(INFO) << "UserScripts: No Match for url_set";
+      return false;
+    }
+  }
+
+  if (!exclude_url_set_.is_empty()) {
+    if (exclude_url_set_.MatchesURL(url)) {
+      if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+        LOG(INFO) << "UserScripts: No Match for exclude_url_set";
+      return false;
+    }
+  }
+
+  if (!globs_.empty()) {
+    if (!UrlMatchesGlobs(&globs_, url)) {
+      if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+        LOG(INFO) << "UserScripts: No Match for globs";
+      return false;
+    }
+  }
+
+  if (!exclude_globs_.empty()) {
+    if (UrlMatchesGlobs(&exclude_globs_, url)) {
+      if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+        LOG(INFO) << "UserScripts: No Match for exclude_globs";
+      return false;
+    }
+  }
+
+  return true;
+}
+
+bool UserScript::MatchesDocument(const GURL& effective_document_url,
+                                 bool is_subframe) const {
+  if (is_subframe && !match_all_frames())
+    return false;
+
+  return MatchesURL(effective_document_url);
+}
+
+void UserScript::File::Pickle(base::Pickle* pickle) const {
+  pickle->WriteString(url_.spec());
+  // Do not write path. It's not needed in the renderer.
+  // Do not write content. It will be serialized by other means.
+}
+
+void UserScript::File::Unpickle(const base::Pickle& pickle,
+                                base::PickleIterator* iter) {
+  // Read the url from the pickle.
+  std::string url;
+  CHECK(iter->ReadString(&url));
+  set_url(GURL(url));
+}
+
+void UserScript::Pickle(base::Pickle* pickle) const {
+  // Write the simple types to the pickle.
+  pickle->WriteInt(run_location());
+  pickle->WriteInt(user_script_id_);
+  pickle->WriteBool(emulate_greasemonkey());
+  pickle->WriteBool(match_all_frames());
+  pickle->WriteInt(static_cast<int>(match_origin_as_fallback()));
+  pickle->WriteBool(is_incognito_enabled());
+
+  PickleHostID(pickle, host_id_);
+  pickle->WriteInt(consumer_instance_type());
+  PickleGlobs(pickle, globs_);
+  PickleGlobs(pickle, exclude_globs_);
+  PickleURLPatternSet(pickle, url_set_);
+  PickleURLPatternSet(pickle, exclude_url_set_);
+  PickleScripts(pickle, js_scripts_);
+  PickleScripts(pickle, css_scripts_);
+}
+
+void UserScript::PickleGlobs(base::Pickle* pickle,
+                             const std::vector<std::string>& globs) const {
+  pickle->WriteUInt32(globs.size());
+  for (auto glob = globs.cbegin(); glob != globs.cend(); ++glob) {
+    pickle->WriteString(*glob);
+  }
+}
+
+void UserScript::PickleHostID(base::Pickle* pickle,
+                              const HostID& host_id) const {
+  pickle->WriteInt(host_id.type());
+  pickle->WriteString(host_id.id());
+}
+
+void UserScript::PickleURLPatternSet(base::Pickle* pickle,
+                                     const URLPatternSet& pattern_list) const {
+  pickle->WriteUInt32(pattern_list.patterns().size());
+  for (auto pattern = pattern_list.begin(); pattern != pattern_list.end();
+       ++pattern) {
+    pickle->WriteInt(pattern->valid_schemes());
+    pickle->WriteString(pattern->GetAsString());
+  }
+}
+
+void UserScript::PickleScripts(base::Pickle* pickle,
+                               const FileList& scripts) const {
+  pickle->WriteUInt32(scripts.size());
+  for (const std::unique_ptr<File>& file : scripts)
+    file->Pickle(pickle);
+}
+
+void UserScript::Unpickle(const base::Pickle& pickle,
+                          base::PickleIterator* iter) {
+  // Read the run location.
+  int run_location = 0;
+  CHECK(iter->ReadInt(&run_location));
+  CHECK(run_location >= 0 && run_location < RUN_LOCATION_LAST);
+  run_location_ = static_cast<RunLocation>(run_location);
+
+  CHECK(iter->ReadInt(&user_script_id_));
+  CHECK(iter->ReadBool(&emulate_greasemonkey_));
+  CHECK(iter->ReadBool(&match_all_frames_));
+  int match_origin_as_fallback_int = 0;
+  CHECK(iter->ReadInt(&match_origin_as_fallback_int));
+  match_origin_as_fallback_ =
+      static_cast<MatchOriginAsFallbackBehavior>(match_origin_as_fallback_int);
+  CHECK(iter->ReadBool(&incognito_enabled_));
+
+  UnpickleHostID(pickle, iter, &host_id_);
+
+  int consumer_instance_type = 0;
+  CHECK(iter->ReadInt(&consumer_instance_type));
+  consumer_instance_type_ =
+      static_cast<ConsumerInstanceType>(consumer_instance_type);
+
+  UnpickleGlobs(pickle, iter, &globs_);
+  UnpickleGlobs(pickle, iter, &exclude_globs_);
+  UnpickleURLPatternSet(pickle, iter, &url_set_);
+  UnpickleURLPatternSet(pickle, iter, &exclude_url_set_);
+  UnpickleScripts(pickle, iter, &js_scripts_);
+  UnpickleScripts(pickle, iter, &css_scripts_);
+}
+
+void UserScript::UnpickleGlobs(const base::Pickle& pickle,
+                               base::PickleIterator* iter,
+                               std::vector<std::string>* globs) {
+  uint32_t num_globs = 0;
+  CHECK(iter->ReadUInt32(&num_globs));
+  globs->clear();
+  for (uint32_t i = 0; i < num_globs; ++i) {
+    std::string glob;
+    CHECK(iter->ReadString(&glob));
+    globs->push_back(glob);
+  }
+}
+
+void UserScript::UnpickleHostID(const base::Pickle& pickle,
+                                base::PickleIterator* iter,
+                                HostID* host_id) {
+  int type = 0;
+  std::string id;
+  CHECK(iter->ReadInt(&type));
+  CHECK(iter->ReadString(&id));
+  *host_id = HostID(static_cast<HostID::HostType>(type), id);
+}
+
+void UserScript::UnpickleURLPatternSet(const base::Pickle& pickle,
+                                       base::PickleIterator* iter,
+                                       URLPatternSet* pattern_list) {
+  uint32_t num_patterns = 0;
+  CHECK(iter->ReadUInt32(&num_patterns));
+
+  pattern_list->ClearPatterns();
+  for (uint32_t i = 0; i < num_patterns; ++i) {
+    int valid_schemes;
+    CHECK(iter->ReadInt(&valid_schemes));
+
+    std::string pattern_str;
+    CHECK(iter->ReadString(&pattern_str));
+
+    URLPattern pattern(kValidUserScriptSchemes);
+    URLPattern::ParseResult result = pattern.Parse(pattern_str);
+    CHECK(URLPattern::ParseResult::kSuccess == result)
+        << URLPattern::GetParseResultString(result) << " "
+        << pattern_str.c_str();
+
+    pattern.SetValidSchemes(valid_schemes);
+    pattern_list->AddPattern(pattern);
+  }
+}
+
+void UserScript::UnpickleScripts(const base::Pickle& pickle,
+                                 base::PickleIterator* iter,
+                                 FileList* scripts) {
+  uint32_t num_files = 0;
+  CHECK(iter->ReadUInt32(&num_files));
+  scripts->clear();
+  for (uint32_t i = 0; i < num_files; ++i) {
+    std::unique_ptr<File> file(new File());
+    file->Unpickle(pickle, iter);
+    scripts->push_back(std::move(file));
+  }
+}
+
+UserScriptIDPair::UserScriptIDPair(int id, const HostID& host_id)
+    : id(id), host_id(host_id) {}
+
+UserScriptIDPair::UserScriptIDPair(int id) : id(id), host_id(HostID()) {}
+
+bool operator<(const UserScriptIDPair& a, const UserScriptIDPair& b) {
+  return a.id < b.id;
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/common/user_script.h b/components/user_scripts/common/user_script.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/user_script.h
@@ -0,0 +1,387 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_COMMON_USER_SCRIPT_H_
+#define USERSCRIPTS_COMMON_USER_SCRIPT_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "base/files/file_path.h"
+#include "base/strings/string_piece.h"
+#include "script_constants.h"
+#include "host_id.h"
+#include "url_pattern.h"
+#include "url_pattern_set.h"
+#include "url/gurl.h"
+
+namespace base {
+class Pickle;
+class PickleIterator;
+}
+
+namespace user_scripts {
+
+// Represents a user script, either a standalone one, or one that is part of an
+// extension.
+class UserScript {
+ public:
+  // The file extension for standalone user scripts.
+  static const char kFileExtension[];
+
+  static int GenerateUserScriptID();
+
+  // Check if a URL should be treated as a user script and converted to an
+  // extension.
+  static bool IsURLUserScript(const GURL& url, const std::string& mime_type);
+
+  // Get the valid user script schemes for the current process. If
+  // canExecuteScriptEverywhere is true, this will return ALL_SCHEMES.
+  static int ValidUserScriptSchemes(bool canExecuteScriptEverywhere = false);
+
+  // TODO(rdevlin.cronin) This and RunLocation don't really belong here, since
+  // they are used for more than UserScripts (e.g., tabs.executeScript()).
+  // The type of injected script.
+  enum InjectionType {
+    // A content script specified in the extension's manifest.
+    CONTENT_SCRIPT,
+    // A script injected via, e.g. tabs.executeScript().
+    //PROGRAMMATIC_SCRIPT
+  };
+  // The last type of injected script; used for enum verification in IPC.
+  // Update this if you add more injected script types!
+  static const InjectionType INJECTION_TYPE_LAST = CONTENT_SCRIPT/*PROGRAMMATIC_SCRIPT*/;
+
+  // Locations that user scripts can be run inside the document.
+  // The three run locations must strictly follow each other in both load order
+  // (i.e., start *always* comes before end) and numerically, as we use
+  // arithmetic checking (e.g., curr == last + 1). So, no bitmasks here!!
+  enum RunLocation {
+    UNDEFINED,
+    DOCUMENT_START,  // After the documentElement is created, but before
+                     // anything else happens.
+    DOCUMENT_END,  // After the entire document is parsed. Same as
+                   // DOMContentLoaded.
+    DOCUMENT_IDLE,  // Sometime after DOMContentLoaded, as soon as the document
+                    // is "idle". Currently this uses the simple heuristic of:
+                    // min(DOM_CONTENT_LOADED + TIMEOUT, ONLOAD), but no
+                    // particular injection point is guaranteed.
+    RUN_DEFERRED,  // The user script's injection was deferred for permissions
+                   // reasons, and was executed at a later time.
+    BROWSER_DRIVEN,  // The user script will be injected when triggered by an
+                     // IPC in the browser process.
+    RUN_LOCATION_LAST  // Leave this as the last item.
+  };
+
+  // Holds script file info.
+  class File {
+   public:
+    File(const base::FilePath& extension_root,
+         const base::FilePath& relative_path,
+         const GURL& url);
+    File();
+    File(const File& other);
+    ~File();
+
+    const base::FilePath& extension_root() const { return extension_root_; }
+    const base::FilePath& relative_path() const { return relative_path_; }
+
+    const GURL& url() const { return url_; }
+    void set_url(const GURL& url) { url_ = url; }
+
+    // If external_content_ is set returns it as content otherwise it returns
+    // content_
+    const base::StringPiece GetContent() const {
+      if (external_content_.data())
+        return external_content_;
+      else
+        return content_;
+    }
+    void set_external_content(const base::StringPiece& content) {
+      external_content_ = content;
+    }
+    void set_content(const base::StringPiece& content) {
+      content_.assign(content.begin(), content.end());
+    }
+
+    const std::string& key() const { return key_; }
+    void set_key(const std::string& key) {
+      key_ = key;
+    }
+
+    // Serialization support. The content and FilePath members will not be
+    // serialized!
+    void Pickle(base::Pickle* pickle) const;
+    void Unpickle(const base::Pickle& pickle, base::PickleIterator* iter);
+
+   private:
+    // Where the script file lives on the disk. We keep the path split so that
+    // it can be localized at will.
+    base::FilePath extension_root_;
+    base::FilePath relative_path_;
+
+    // The url to this script file.
+    GURL url_;
+
+    // The script content. It can be set to either loaded_content_ or
+    // externally allocated string.
+    base::StringPiece external_content_;
+
+    // Set when the content is loaded by LoadContent
+    std::string content_;
+
+    std::string key_;
+  };
+
+  using FileList = std::vector<std::unique_ptr<File>>;
+
+  // Type of a API consumer instance that user scripts will be injected on.
+  enum ConsumerInstanceType { TAB, WEBVIEW };
+
+  // Constructor. Default the run location to document end, which is like
+  // Greasemonkey and probably more useful for typical scripts.
+  UserScript();
+  ~UserScript();
+
+  // Performs a copy of all fields except file contents.
+  // static std::unique_ptr<UserScript> CopyMetadataFrom(const UserScript& other);
+
+  const std::string& name_space() const { return name_space_; }
+  void set_name_space(const std::string& name_space) {
+    name_space_ = name_space;
+  }
+
+  const std::string& name() const { return name_; }
+  void set_name(const std::string& name) { name_ = name; }
+
+  const std::string& version() const { return version_; }
+  void set_version(const std::string& version) {
+    version_ = version;
+  }
+
+  const std::string& key() const { return key_; }
+  void set_key(const std::string& key) {
+    key_ = key;
+  }
+
+  const std::string& file_path() const { return file_path_; }
+  void set_file_path(const std::string& file_path) {
+    file_path_ = file_path;
+  }
+
+  const std::string& url_source() const { return url_source_; }
+  void set_url_source(const std::string& url_source) {
+    url_source_ = url_source;
+  }
+
+  const std::string& description() const { return description_; }
+  void set_description(const std::string& description) {
+    description_ = description;
+  }
+
+  // The place in the document to run the script.
+  RunLocation run_location() const { return run_location_; }
+  void set_run_location(RunLocation location) { run_location_ = location; }
+
+  // Whether to emulate greasemonkey when running this script.
+  bool emulate_greasemonkey() const { return emulate_greasemonkey_; }
+  void set_emulate_greasemonkey(bool val) { emulate_greasemonkey_ = val; }
+
+  // Whether to match all frames, or only the top one.
+  bool match_all_frames() const { return match_all_frames_; }
+  void set_match_all_frames(bool val) { match_all_frames_ = val; }
+
+  // Whether to match the origin as a fallback if the URL cannot be used
+  // directly.
+  MatchOriginAsFallbackBehavior match_origin_as_fallback() const {
+    return match_origin_as_fallback_;
+  }
+  void set_match_origin_as_fallback(MatchOriginAsFallbackBehavior val) {
+    match_origin_as_fallback_ = val;
+  }
+
+  // The globs, if any, that determine which pages this script runs against.
+  // These are only used with "standalone" Greasemonkey-like user scripts.
+  const std::vector<std::string>& globs() const { return globs_; }
+  void add_glob(const std::string& glob) { globs_.push_back(glob); }
+  void clear_globs() { globs_.clear(); }
+  const std::vector<std::string>& exclude_globs() const {
+    return exclude_globs_;
+  }
+  void add_exclude_glob(const std::string& glob) {
+    exclude_globs_.push_back(glob);
+  }
+  void clear_exclude_globs() { exclude_globs_.clear(); }
+
+  // The URLPatterns, if any, that determine which pages this script runs
+  // against.
+  const URLPatternSet& url_patterns() const { return url_set_; }
+  void add_url_pattern(const URLPattern& pattern);
+  const URLPatternSet& exclude_url_patterns() const {
+    return exclude_url_set_;
+  }
+  void add_exclude_url_pattern(const URLPattern& pattern);
+
+  // List of js scripts for this user script
+  FileList& js_scripts() { return js_scripts_; }
+  const FileList& js_scripts() const { return js_scripts_; }
+
+  // List of css scripts for this user script
+  FileList& css_scripts() { return css_scripts_; }
+  const FileList& css_scripts() const { return css_scripts_; }
+
+  const std::string& extension_id() const { return host_id_.id(); }
+
+  const HostID& host_id() const { return host_id_; }
+  void set_host_id(const HostID& host_id) { host_id_ = host_id; }
+
+  const ConsumerInstanceType& consumer_instance_type() const {
+    return consumer_instance_type_;
+  }
+  void set_consumer_instance_type(
+      const ConsumerInstanceType& consumer_instance_type) {
+    consumer_instance_type_ = consumer_instance_type;
+  }
+
+  int id() const { return user_script_id_; }
+  void set_id(int id) { user_script_id_ = id; }
+
+  // TODO(lazyboy): Incognito information is extension specific, it doesn't
+  // belong here. We should be able to determine this in the renderer/ where it
+  // is used.
+  bool is_incognito_enabled() const { return incognito_enabled_; }
+  void set_incognito_enabled(bool enabled) { incognito_enabled_ = enabled; }
+
+  // Returns true if the script should be applied to the specified URL, false
+  // otherwise.
+  bool MatchesURL(const GURL& url) const;
+
+  // Returns true if the script should be applied to the given
+  // |effective_document_url|. It is the caller's responsibility to calculate
+  // |effective_document_url| based on match_origin_as_fallback().
+  bool MatchesDocument(const GURL& effective_document_url,
+                       bool is_subframe) const;
+
+  // Serializes the UserScript into a pickle. The content of the scripts and
+  // paths to UserScript::Files will not be serialized!
+  void Pickle(base::Pickle* pickle) const;
+
+  // Deserializes the script from a pickle. Note that this always succeeds
+  // because presumably we were the one that pickled it, and we did it
+  // correctly.
+  void Unpickle(const base::Pickle& pickle, base::PickleIterator* iter);
+
+ private:
+  // base::Pickle helper functions used to pickle the individual types of
+  // components.
+  void PickleGlobs(base::Pickle* pickle,
+                   const std::vector<std::string>& globs) const;
+  void PickleHostID(base::Pickle* pickle, const HostID& host_id) const;
+  void PickleURLPatternSet(base::Pickle* pickle,
+                           const URLPatternSet& pattern_list) const;
+  void PickleScripts(base::Pickle* pickle, const FileList& scripts) const;
+
+  // Unpickle helper functions used to unpickle individual types of components.
+  void UnpickleGlobs(const base::Pickle& pickle,
+                     base::PickleIterator* iter,
+                     std::vector<std::string>* globs);
+  void UnpickleHostID(const base::Pickle& pickle,
+                      base::PickleIterator* iter,
+                      HostID* host_id);
+  void UnpickleURLPatternSet(const base::Pickle& pickle,
+                             base::PickleIterator* iter,
+                             URLPatternSet* pattern_list);
+  void UnpickleScripts(const base::Pickle& pickle,
+                       base::PickleIterator* iter,
+                       FileList* scripts);
+
+  // The location to run the script inside the document.
+  RunLocation run_location_ = DOCUMENT_IDLE;
+
+  // The namespace of the script. This is used by Greasemonkey in the same way
+  // as XML namespaces. Only used when parsing Greasemonkey-style scripts.
+  std::string name_space_;
+
+  // The script's name. Only used when parsing Greasemonkey-style scripts.
+  std::string name_;
+
+  // A longer description. Only used when parsing Greasemonkey-style scripts.
+  std::string description_;
+
+  // A version number of the script. Only used when parsing Greasemonkey-style
+  // scripts.
+  std::string version_;
+
+  // Greasemonkey-style globs that determine pages to inject the script into.
+  // These are only used with standalone scripts.
+  std::vector<std::string> globs_;
+  std::vector<std::string> exclude_globs_;
+
+  // URLPatterns that determine pages to inject the script into. These are
+  // only used with scripts that are part of extensions.
+  URLPatternSet url_set_;
+  URLPatternSet exclude_url_set_;
+
+  // List of js scripts defined in content_scripts
+  FileList js_scripts_;
+
+  // List of css scripts defined in content_scripts
+  FileList css_scripts_;
+
+  // internal key of scripts
+  std::string key_;
+
+  std::string file_path_;
+
+  // url source of script
+  std::string url_source_;
+
+  // The ID of the host this script is a part of. The |ID| of the
+  // |host_id| can be empty if the script is a "standlone" user script.
+  HostID host_id_;
+
+  // The type of the consumer instance that the script will be injected.
+  ConsumerInstanceType consumer_instance_type_ = TAB;
+
+  // The globally-unique id associated with this user script. -1 indicates
+  // "invalid".
+  int user_script_id_ = -1;
+
+  // Whether we should try to emulate Greasemonkey's APIs when running this
+  // script.
+  bool emulate_greasemonkey_ = false;
+
+  // Whether the user script should run in all frames, or only just the top one.
+  bool match_all_frames_ = false;
+
+  // Whether the user script should run in frames whose initiator / precursor
+  // origin matches a match pattern, if an appropriate URL cannot be found for
+  // the frame for matching purposes, such as in the case of about:, data:, and
+  // other schemes.
+  MatchOriginAsFallbackBehavior match_origin_as_fallback_ =
+      MatchOriginAsFallbackBehavior::kNever;
+
+  // True if the script should be injected into an incognito tab.
+  bool incognito_enabled_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(UserScript);
+};
+
+// Information we need while removing scripts from a UserScriptLoader.
+struct UserScriptIDPair {
+  UserScriptIDPair(int id, const HostID& host_id);
+  explicit UserScriptIDPair(int id);
+
+  int id;
+  HostID host_id;
+};
+
+bool operator<(const UserScriptIDPair& a, const UserScriptIDPair& b);
+
+using UserScriptList = std::vector<std::unique_ptr<UserScript>>;
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_COMMON_USER_SCRIPT_H_
diff --git a/components/user_scripts/common/user_scripts_features.cc b/components/user_scripts/common/user_scripts_features.cc
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/common/user_scripts_features.cc
@@ -0,0 +1,34 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include "user_scripts_features.h"
+
+#include "build/build_config.h"
+
+namespace user_scripts {
+
+namespace features {
+
+const base::Feature kEnableUserScripts = {"EnableUserScripts",
+                                          base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kEnableLoggingUserScripts =
+                                        {"EnableLoggingUserScripts",
+                                          base::FEATURE_DISABLED_BY_DEFAULT};
+
+}
+
+}
\ No newline at end of file
diff --git a/components/user_scripts/common/user_scripts_features.h b/components/user_scripts/common/user_scripts_features.h
new file mode 100644
--- /dev/null
+++ b/components/user_scripts/common/user_scripts_features.h
@@ -0,0 +1,35 @@
+/*
+    This file is part of Bromite.
+
+    Bromite is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Bromite is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Bromite. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#ifndef USERSCRIPTS_COMMON_USERSCRIPTS_FEATURES_H_
+#define USERSCRIPTS_COMMON_USERSCRIPTS_FEATURES_H_
+
+// This file defines all the base::FeatureList features for the Password Manager
+// module.
+
+#include "base/feature_list.h"
+
+namespace user_scripts {
+
+namespace features {
+    extern const base::Feature kEnableUserScripts;
+    extern const base::Feature kEnableLoggingUserScripts;
+}
+
+}
+
+#endif
\ No newline at end of file
diff --git a/components/user_scripts/common/view_type.cc b/components/user_scripts/common/view_type.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/view_type.cc
@@ -0,0 +1,39 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "view_type.h"
+
+#include "base/strings/string_piece.h"
+
+namespace user_scripts {
+
+bool GetViewTypeFromString(const std::string& view_type,
+                           ViewType* view_type_out) {
+  // TODO(devlin): This map doesn't contain the following values:
+  // - VIEW_TYPE_BACKGROUND_CONTENTS
+  // - VIEW_TYPE_COMPONENT
+  // - VIEW_TYPE_EXTENSION_GUEST
+  // Why? Is it just because we don't expose those types to JS?
+  static const struct {
+    ViewType type;
+    base::StringPiece name;
+  } constexpr kTypeMap[] = {
+      // {VIEW_TYPE_APP_WINDOW, "APP_WINDOW"},
+      // {VIEW_TYPE_EXTENSION_BACKGROUND_PAGE, "BACKGROUND"},
+      // {VIEW_TYPE_EXTENSION_DIALOG, "EXTENSION_DIALOG"},
+      // {VIEW_TYPE_EXTENSION_POPUP, "POPUP"},
+      {VIEW_TYPE_TAB_CONTENTS, "TAB"},
+  };
+
+  for (const auto& entry : kTypeMap) {
+    if (entry.name == view_type) {
+      *view_type_out = entry.type;
+      return true;
+    }
+  }
+
+  return false;
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/common/view_type.h b/components/user_scripts/common/view_type.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/common/view_type.h
@@ -0,0 +1,48 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_COMMON_VIEW_TYPE_H_
+#define USERSCRIPTS_COMMON_VIEW_TYPE_H_
+
+#include <string>
+
+namespace user_scripts {
+
+// Icky RTTI used by a few systems to distinguish the host type of a given
+// WebContents.
+//
+// Do not change or reuse the the entry values in this list as this is used in
+// ExtensionViewType enum in tools/metrics/histograms/enums.xml.
+//
+// TODO(aa): Remove this and teach those systems to keep track of their own
+// data.
+enum ViewType {
+  VIEW_TYPE_INVALID = 0,
+  // VIEW_TYPE_APP_WINDOW = 1,
+  // VIEW_TYPE_BACKGROUND_CONTENTS = 2,
+
+  // // For custom parts of Chrome if no other type applies.
+  // VIEW_TYPE_COMPONENT = 3,
+
+  // VIEW_TYPE_EXTENSION_BACKGROUND_PAGE = 4,
+  // VIEW_TYPE_EXTENSION_DIALOG = 5,
+  // VIEW_TYPE_EXTENSION_GUEST = 6,
+  // VIEW_TYPE_EXTENSION_POPUP = 7,
+
+  // Panels were removed in https://crbug.com/571511.
+  // DEPRECATED_VIEW_TYPE_PANEL = 8,
+
+  VIEW_TYPE_TAB_CONTENTS = 9,
+
+  VIEW_TYPE_LAST = VIEW_TYPE_TAB_CONTENTS
+};
+
+// Matches the |view_type| to the corresponding ViewType, and populates
+// |view_type_out|. Returns true if a match is found.
+bool GetViewTypeFromString(const std::string& view_type,
+                           ViewType* view_type_out);
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_COMMON_VIEW_TYPE_H_
diff --git a/components/user_scripts/renderer/BUILD.gn b/components/user_scripts/renderer/BUILD.gn
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/BUILD.gn
@@ -0,0 +1,67 @@
+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//tools/grit/grit_rule.gni")
+import("//tools/grit/repack.gni")
+
+group("user_scripts_resources") {
+  public_deps = [
+    ":user_scripts_renderer_resources",
+  ]
+}
+
+grit("user_scripts_renderer_resources") {
+  source = "resources/user_scripts_renderer_resources.grd"
+  outputs = [
+    "grit/user_scripts_renderer_resources.h",
+    "user_scripts_renderer_resources.pak",
+  ]
+  grit_flags = [
+    "-E",
+    "mojom_root=" + rebase_path(root_gen_dir, root_build_dir),
+  ]
+}
+
+static_library("renderer") {
+  sources = [
+    "extension_frame_helper.cc",
+    "extension_frame_helper.h",
+    "injection_host.cc",
+    "injection_host.h",
+    "script_injection_manager.cc",
+    "script_injection_manager.h",
+    "script_injection_callback.cc",
+    "script_injection_callback.h",
+    "script_injection.cc",
+    "script_injection.h",
+    "script_injector.h",
+    "script_context.cc",
+    "script_context.h",
+    "scripts_run_info.cc",
+    "scripts_run_info.h",
+    "user_script_injector.cc",
+    "user_script_injector.h",
+    "user_script_set_manager.cc",
+    "user_script_set_manager.h",
+    "user_script_set.cc",
+    "user_script_set.h",
+    "user_scripts_dispatcher.cc",
+    "user_scripts_dispatcher.h",
+    "user_scripts_renderer_client.cc",
+    "user_scripts_renderer_client.h",
+    "web_ui_injection_host.cc",
+    "web_ui_injection_host.h",
+  ]
+
+  deps = [
+    ":user_scripts_resources",
+    "//base",
+    "//content/public/common",
+    "//content/public/renderer",
+    "//components/user_scripts/common",
+    "//mojo/public/cpp/bindings",
+    "//third_party/blink/public:blink_headers",
+    "//v8",
+  ]
+}
diff --git a/components/user_scripts/renderer/extension_frame_helper.cc b/components/user_scripts/renderer/extension_frame_helper.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/extension_frame_helper.cc
@@ -0,0 +1,96 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "extension_frame_helper.h"
+
+#include <set>
+
+#include "base/metrics/histogram_macros.h"
+#include "base/strings/string_util.h"
+#include "base/timer/elapsed_timer.h"
+#include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/render_view.h"
+#include "../common/constants.h"
+#include "third_party/blink/public/platform/web_security_origin.h"
+#include "third_party/blink/public/web/web_console_message.h"
+#include "third_party/blink/public/web/web_document.h"
+#include "third_party/blink/public/web/web_document_loader.h"
+#include "third_party/blink/public/web/web_local_frame.h"
+#include "third_party/blink/public/web/web_settings.h"
+#include "third_party/blink/public/web/web_view.h"
+
+namespace user_scripts {
+
+namespace {
+
+base::LazyInstance<std::set<const ExtensionFrameHelper*>>::DestructorAtExit
+    g_frame_helpers = LAZY_INSTANCE_INITIALIZER;
+
+// Runs every callback in |callbacks_to_be_run_and_cleared| while |frame_helper|
+// is valid, and clears |callbacks_to_be_run_and_cleared|.
+void RunCallbacksWhileFrameIsValid(
+    base::WeakPtr<ExtensionFrameHelper> frame_helper,
+    std::vector<base::OnceClosure>* callbacks_to_be_run_and_cleared) {
+  // The JavaScript code can cause re-entrancy. To avoid a deadlock, don't run
+  // callbacks that are added during the iteration.
+  std::vector<base::OnceClosure> callbacks;
+  callbacks_to_be_run_and_cleared->swap(callbacks);
+  for (auto& callback : callbacks) {
+    std::move(callback).Run();
+    if (!frame_helper.get())
+      return;  // Frame and ExtensionFrameHelper invalidated by callback.
+  }
+}
+
+}  // namespace
+
+ExtensionFrameHelper::ExtensionFrameHelper(content::RenderFrame* render_frame)
+    : content::RenderFrameObserver(render_frame),
+      content::RenderFrameObserverTracker<ExtensionFrameHelper>(render_frame),
+      tab_id_(-1) {
+  g_frame_helpers.Get().insert(this);
+}
+
+ExtensionFrameHelper::~ExtensionFrameHelper() {
+  g_frame_helpers.Get().erase(this);
+}
+
+void ExtensionFrameHelper::ScheduleAtDocumentStart(
+    base::OnceClosure callback) {
+  document_element_created_callbacks_.push_back(std::move(callback));
+}
+
+void ExtensionFrameHelper::ScheduleAtDocumentEnd(
+    base::OnceClosure callback) {
+  document_load_finished_callbacks_.push_back(std::move(callback));
+}
+
+void ExtensionFrameHelper::ScheduleAtDocumentIdle(
+    base::OnceClosure callback) {
+  document_idle_callbacks_.push_back(std::move(callback));
+}
+
+void ExtensionFrameHelper::RunScriptsAtDocumentStart() {
+  RunCallbacksWhileFrameIsValid(weak_ptr_factory_.GetWeakPtr(),
+                                &document_element_created_callbacks_);
+  // |this| might be dead by now.
+}
+
+void ExtensionFrameHelper::RunScriptsAtDocumentEnd() {
+  RunCallbacksWhileFrameIsValid(weak_ptr_factory_.GetWeakPtr(),
+                                &document_load_finished_callbacks_);
+  // |this| might be dead by now.
+}
+
+void ExtensionFrameHelper::RunScriptsAtDocumentIdle() {
+  RunCallbacksWhileFrameIsValid(weak_ptr_factory_.GetWeakPtr(),
+                                &document_idle_callbacks_);
+  // |this| might be dead by now.
+}
+
+void ExtensionFrameHelper::OnDestruct() {
+  delete this;
+}
+
+}  // namespace user_scripts
diff --git a/components/user_scripts/renderer/extension_frame_helper.h b/components/user_scripts/renderer/extension_frame_helper.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/extension_frame_helper.h
@@ -0,0 +1,92 @@
+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_EXTENSION_FRAME_HELPER_H_
+#define USERSCRIPTS_RENDERER_EXTENSION_FRAME_HELPER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/callback_forward.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "content/public/renderer/render_frame_observer.h"
+#include "content/public/renderer/render_frame_observer_tracker.h"
+#include "../common/view_type.h"
+#include "third_party/blink/public/mojom/devtools/console_message.mojom.h"
+#include "v8/include/v8.h"
+
+struct ExtensionMsg_ExternalConnectionInfo;
+struct ExtensionMsg_TabConnectionInfo;
+
+namespace base {
+class ListValue;
+}
+
+namespace user_scripts {
+
+class Dispatcher;
+struct Message;
+struct PortId;
+class ScriptContext;
+
+// RenderFrame-level plumbing for extension features.
+class ExtensionFrameHelper
+    : public content::RenderFrameObserver,
+      public content::RenderFrameObserverTracker<ExtensionFrameHelper> {
+ public:
+  ExtensionFrameHelper(content::RenderFrame* render_frame /*,
+                       Dispatcher* extension_dispatcher*/);
+  ~ExtensionFrameHelper() override;
+
+  int tab_id() const { return tab_id_; }
+
+  // Called when the document element has been inserted in this frame. This
+  // method may invoke untrusted JavaScript code that invalidate the frame and
+  // this ExtensionFrameHelper.
+  void RunScriptsAtDocumentStart();
+
+  // Called after the DOMContentLoaded event has fired.
+  void RunScriptsAtDocumentEnd();
+
+  // Called before the window.onload event is fired.
+  void RunScriptsAtDocumentIdle();
+
+  // Schedule a callback, to be run at the next RunScriptsAtDocumentStart
+  // notification. Only call this when you are certain that there will be such a
+  // notification, e.g. from RenderFrameObserver::DidCreateDocumentElement.
+  // Otherwise the callback is never invoked, or invoked for a document that you
+  // were not expecting.
+  void ScheduleAtDocumentStart(base::OnceClosure callback);
+
+  // Schedule a callback, to be run at the next RunScriptsAtDocumentEnd call.
+  void ScheduleAtDocumentEnd(base::OnceClosure callback);
+
+  // Schedule a callback, to be run at the next RunScriptsAtDocumentIdle call.
+  void ScheduleAtDocumentIdle(base::OnceClosure callback);
+
+ private:
+
+  void OnDestruct() override;
+
+  // The id of the tab the render frame is attached to.
+  int tab_id_;
+
+  // Callbacks to be run at the next RunScriptsAtDocumentStart notification.
+  std::vector<base::OnceClosure> document_element_created_callbacks_;
+
+  // Callbacks to be run at the next RunScriptsAtDocumentEnd notification.
+  std::vector<base::OnceClosure> document_load_finished_callbacks_;
+
+  // Callbacks to be run at the next RunScriptsAtDocumentIdle notification.
+  std::vector<base::OnceClosure> document_idle_callbacks_;
+
+  base::WeakPtrFactory<ExtensionFrameHelper> weak_ptr_factory_{this};
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionFrameHelper);
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_RENDERER_EXTENSION_FRAME_HELPER_H_
diff --git a/components/user_scripts/renderer/injection_host.cc b/components/user_scripts/renderer/injection_host.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/injection_host.cc
@@ -0,0 +1,12 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "injection_host.h"
+
+InjectionHost::InjectionHost(const HostID& host_id) :
+    id_(host_id) {
+}
+
+InjectionHost::~InjectionHost() {
+}
diff --git a/components/user_scripts/renderer/injection_host.h b/components/user_scripts/renderer/injection_host.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/injection_host.h
@@ -0,0 +1,42 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_INJECTION_HOST_H_
+#define USERSCRIPTS_RENDERER_INJECTION_HOST_H_
+
+#include "base/macros.h"
+#include "../common/host_id.h"
+#include "url/gurl.h"
+
+namespace content {
+class RenderFrame;
+}
+
+// An interface for all kinds of hosts who own user scripts.
+class InjectionHost {
+ public:
+  InjectionHost(const HostID& host_id);
+  virtual ~InjectionHost();
+
+  // Returns the CSP to be used for the isolated world. Currently this only
+  // bypasses the main world CSP. If null is returned, the main world CSP is not
+  // bypassed.
+  virtual const std::string* GetContentSecurityPolicy() const = 0;
+
+  // The base url for the host.
+  virtual const GURL& url() const = 0;
+
+  // The human-readable name of the host.
+  virtual const std::string& name() const = 0;
+
+  const HostID& id() const { return id_; }
+
+ private:
+  // The ID of the host.
+  HostID id_;
+
+  DISALLOW_COPY_AND_ASSIGN(InjectionHost);
+};
+
+#endif  // USERSCRIPTS_RENDERER_INJECTION_HOST_H_
diff --git a/components/user_scripts/renderer/resources/greasemonkey_api.js b/components/user_scripts/renderer/resources/greasemonkey_api.js
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/resources/greasemonkey_api.js
@@ -0,0 +1,82 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// -----------------------------------------------------------------------------
+// NOTE: If you change this file you need to touch renderer_resources.grd to
+// have your change take effect.
+// -----------------------------------------------------------------------------
+
+// Partial implementation of the Greasemonkey API, see:
+// http://wiki.greasespot.net/Greasemonkey_Manual:APIs
+
+function GM_addStyle(css) {
+  var parent = document.getElementsByTagName("head")[0];
+  if (!parent) {
+    parent = document.documentElement;
+  }
+  var style = document.createElement("style");
+  style.type = "text/css";
+  var textNode = document.createTextNode(css);
+  style.appendChild(textNode);
+  parent.appendChild(style);
+}
+
+function GM_xmlhttpRequest(details) {
+  function setupEvent(xhr, url, eventName, callback) {
+    xhr[eventName] = function () {
+      var isComplete = xhr.readyState == 4;
+      var responseState = {
+        responseText: xhr.responseText,
+        readyState: xhr.readyState,
+        responseHeaders: isComplete ? xhr.getAllResponseHeaders() : "",
+        status: isComplete ? xhr.status : 0,
+        statusText: isComplete ? xhr.statusText : "",
+        finalUrl: isComplete ? url : ""
+      };
+      callback(responseState);
+    };
+  }
+
+  var xhr = new XMLHttpRequest();
+  var eventNames = ["onload", "onerror", "onreadystatechange"];
+  for (var i = 0; i < eventNames.length; i++ ) {
+    var eventName = eventNames[i];
+    if (eventName in details) {
+      setupEvent(xhr, details.url, eventName, details[eventName]);
+    }
+  }
+
+  xhr.open(details.method, details.url);
+
+  if (details.overrideMimeType) {
+    xhr.overrideMimeType(details.overrideMimeType);
+  }
+  if (details.headers) {
+    for (var header in details.headers) {
+      xhr.setRequestHeader(header, details.headers[header]);
+    }
+  }
+  xhr.send(details.data ? details.data : null);
+}
+
+function GM_openInTab(url) {
+  window.open(url, "");
+}
+
+function GM_log(message) {
+  window.console.log(message);
+}
+
+(function() {
+  function generateGreasemonkeyStub(name) {
+    return function() {
+      console.log("%s is not supported.", name);
+    };
+  }
+
+  var apis = ["GM_getValue", "GM_setValue", "GM_registerMenuCommand"];
+  for (var i = 0, api; api = apis[i]; i++) {
+    window[api] = generateGreasemonkeyStub(api);
+  }
+})();
diff --git a/components/user_scripts/renderer/resources/user_scripts_renderer_resources.grd b/components/user_scripts/renderer/resources/user_scripts_renderer_resources.grd
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/resources/user_scripts_renderer_resources.grd
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<grit latest_public_release="0" current_release="1" output_all_resource_defines="false">
+  <outputs>
+    <output filename="grit/user_scripts_renderer_resources.h" type="rc_header">
+      <emit emit_type='prepend'></emit>
+    </output>
+    <output filename="user_scripts_renderer_resources.pak" type="data_package" />
+  </outputs>
+  <release seq="1">
+    <includes>
+      <include name="IDR_GREASEMONKEY_API_JS" file="greasemonkey_api.js" type="BINDATA" />
+    </includes>
+  </release>
+</grit>
diff --git a/components/user_scripts/renderer/script_context.cc b/components/user_scripts/renderer/script_context.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/script_context.cc
@@ -0,0 +1,213 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "script_context.h"
+
+#include "base/command_line.h"
+#include "base/containers/flat_set.h"
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "base/values.h"
+#include "content/public/common/content_switches.h"
+#include "content/public/common/url_constants.h"
+#include "content/public/renderer/render_frame.h"
+#include "../common/constants.h"
+#include "third_party/blink/public/mojom/service_worker/service_worker_registration.mojom.h"
+#include "third_party/blink/public/platform/web_security_origin.h"
+#include "third_party/blink/public/web/web_document.h"
+#include "third_party/blink/public/web/web_document_loader.h"
+#include "third_party/blink/public/web/web_local_frame.h"
+#include "third_party/blink/public/web/web_navigation_params.h"
+#include "v8/include/v8.h"
+
+namespace user_scripts {
+
+namespace {
+
+GURL GetEffectiveDocumentURL(
+    blink::WebLocalFrame* frame,
+    const GURL& document_url,
+    MatchOriginAsFallbackBehavior match_origin_as_fallback,
+    bool allow_inaccessible_parents) {
+  auto should_consider_origin = [document_url, match_origin_as_fallback]() {
+    switch (match_origin_as_fallback) {
+      case MatchOriginAsFallbackBehavior::kNever:
+        return false;
+      case MatchOriginAsFallbackBehavior::kMatchForAboutSchemeAndClimbTree:
+        return document_url.SchemeIs(url::kAboutScheme);
+      case MatchOriginAsFallbackBehavior::kAlways:
+        // TODO(devlin): Add more schemes here - blob, filesystem, etc.
+        return document_url.SchemeIs(url::kAboutScheme) ||
+               document_url.SchemeIs(url::kDataScheme);
+    }
+
+    NOTREACHED();
+  };
+
+  // If we don't need to consider the origin, we're done.
+  if (!should_consider_origin())
+    return document_url;
+
+  // Get the "security origin" for the frame. For about: frames, this is the
+  // origin of that of the controlling frame - e.g., an about:blank frame on
+  // https://example.com will have the security origin of https://example.com.
+  // Other frames, like data: frames, will have an opaque origin. For these,
+  // we can get the precursor origin.
+  const blink::WebSecurityOrigin web_frame_origin = frame->GetSecurityOrigin();
+  const url::Origin frame_origin = web_frame_origin;
+  const url::SchemeHostPort& tuple_or_precursor_tuple =
+      frame_origin.GetTupleOrPrecursorTupleIfOpaque();
+
+  // When there's no valid tuple (which can happen in the case of e.g. a
+  // browser-initiated navigation to an opaque URL), there's no origin to
+  // fallback to. Bail.
+  if (!tuple_or_precursor_tuple.IsValid())
+    return document_url;
+
+  const url::Origin origin_or_precursor_origin =
+      url::Origin::Create(tuple_or_precursor_tuple.GetURL());
+
+  if (!allow_inaccessible_parents &&
+      !web_frame_origin.CanAccess(
+          blink::WebSecurityOrigin(origin_or_precursor_origin))) {
+    // The frame can't access its precursor. Bail.
+    return document_url;
+  }
+
+  // Looks like the initiator origin is an appropriate fallback!
+
+  if (match_origin_as_fallback == MatchOriginAsFallbackBehavior::kAlways) {
+    // The easy case! We use the origin directly. We're done.
+    return origin_or_precursor_origin.GetURL();
+  }
+
+  DCHECK_EQ(MatchOriginAsFallbackBehavior::kMatchForAboutSchemeAndClimbTree,
+            match_origin_as_fallback);
+
+  // Unfortunately, in this case, we have to climb the frame tree. This is for
+  // match patterns that are associated with paths as well, not just origins.
+  // For instance, if an extension wants to run on google.com/maps/* with
+  // match_about_blank true, then it should run on about:-scheme frames created
+  // by google.com/maps, but not about:-scheme frames created by google.com
+  // (which is what the precursor tuple origin would be).
+
+  // Traverse the frame/window hierarchy to find the closest non-about:-page
+  // with the same origin as the precursor and return its URL.
+  // Note: This can return the incorrect result, e.g. if a parent frame
+  // navigates a grandchild frame.
+  blink::WebFrame* parent = frame;
+  GURL parent_url;
+  blink::WebDocument parent_document;
+  base::flat_set<blink::WebFrame*> already_visited_frames;
+  do {
+    already_visited_frames.insert(parent);
+    if (parent->Parent())
+      parent = parent->Parent();
+    else
+      parent = parent->Opener();
+
+    // Avoid an infinite loop - see https://crbug.com/568432 and
+    // https://crbug.com/883526.
+    if (base::Contains(already_visited_frames, parent))
+      return document_url;
+
+    parent_document = parent && parent->IsWebLocalFrame()
+                          ? parent->ToWebLocalFrame()->GetDocument()
+                          : blink::WebDocument();
+
+    // We reached the end of the ancestral chain without finding a valid parent,
+    // or found a remote web frame (in which case, it's a different origin).
+    // Bail and use the original URL.
+    if (parent_document.IsNull())
+      return document_url;
+
+    url::SchemeHostPort parent_tuple_or_precursor_tuple =
+        url::Origin(parent->GetSecurityOrigin())
+            .GetTupleOrPrecursorTupleIfOpaque();
+    if (!parent_tuple_or_precursor_tuple.IsValid() ||
+        parent_tuple_or_precursor_tuple != tuple_or_precursor_tuple) {
+      // The parent has a different tuple origin than frame; this could happen
+      // in edge cases where a parent navigates an iframe or popup of a child
+      // frame at a different origin. [1] In this case, bail, since we can't
+      // find a full URL (i.e., one including the path) with the same security
+      // origin to use for the frame in question.
+      // [1] Consider a frame tree like:
+      // <html> <!--example.com-->
+      //   <iframe id="a" src="a.com">
+      //     <iframe id="b" src="b.com"></iframe>
+      //   </iframe>
+      // </html>
+      // Frame "a" is cross-origin from the top-level frame, and so the
+      // example.com top-level frame can't directly access frame "b". However,
+      // it can navigate it through
+      // window.frames[0].frames[0].location.href = 'about:blank';
+      // In that case, the precursor origin tuple origin of frame "b" would be
+      // example.com, but the parent tuple origin is a.com.
+      // Note that usually, this would have bailed earlier with a remote frame,
+      // but it may not if we're at the process limit.
+      return document_url;
+    }
+
+    parent_url = GURL(parent_document.Url());
+  } while (parent_url.SchemeIs(url::kAboutScheme));
+
+  DCHECK(!parent_url.is_empty());
+  DCHECK(!parent_document.IsNull());
+
+  // We should know that the frame can access the parent document (unless we
+  // explicitly allow it not to), since it has the same tuple origin as the
+  // frame, and we checked the frame access above.
+  DCHECK(allow_inaccessible_parents ||
+         web_frame_origin.CanAccess(parent_document.GetSecurityOrigin()));
+  return parent_url;
+}
+
+using FrameToDocumentLoader =
+    base::flat_map<blink::WebLocalFrame*, blink::WebDocumentLoader*>;
+
+FrameToDocumentLoader& FrameDocumentLoaderMap() {
+  static base::NoDestructor<FrameToDocumentLoader> map;
+  return *map;
+}
+
+blink::WebDocumentLoader* CurrentDocumentLoader(
+    const blink::WebLocalFrame* frame) {
+  auto& map = FrameDocumentLoaderMap();
+  auto it = map.find(frame);
+  return it == map.end() ? frame->GetDocumentLoader() : it->second;
+}
+
+}  // namespace
+
+// static
+GURL ScriptContext::GetDocumentLoaderURLForFrame(
+    const blink::WebLocalFrame* frame) {
+  // Normally we would use frame->document().url() to determine the document's
+  // URL, but to decide whether to inject a content script, we use the URL from
+  // the data source. This "quirk" helps prevents content scripts from
+  // inadvertently adding DOM elements to the compose iframe in Gmail because
+  // the compose iframe's dataSource URL is about:blank, but the document URL
+  // changes to match the parent document after Gmail document.writes into
+  // it to create the editor.
+  // http://code.google.com/p/chromium/issues/detail?id=86742
+  blink::WebDocumentLoader* document_loader = CurrentDocumentLoader(frame);
+  return document_loader ? GURL(document_loader->GetUrl()) : GURL();
+}
+
+// static
+GURL ScriptContext::GetEffectiveDocumentURLForInjection(
+    blink::WebLocalFrame* frame,
+    const GURL& document_url,
+    MatchOriginAsFallbackBehavior match_origin_as_fallback) {
+  // We explicitly allow inaccessible parents here. Extensions should still be
+  // able to inject into a sandboxed iframe if it has access to the embedding
+  // origin.
+  constexpr bool allow_inaccessible_parents = true;
+  return GetEffectiveDocumentURL(frame, document_url, match_origin_as_fallback,
+                                 allow_inaccessible_parents);
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/renderer/script_context.h b/components/user_scripts/renderer/script_context.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/script_context.h
@@ -0,0 +1,70 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_SCRIPT_CONTEXT_H_
+#define USERSCRIPTS_RENDERER_SCRIPT_CONTEXT_H_
+
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "base/threading/thread_checker.h"
+#include "base/unguessable_token.h"
+#include "../common/script_constants.h"
+#include "script_injection_callback.h"
+#include "url/gurl.h"
+#include "v8/include/v8.h"
+
+namespace blink {
+class WebDocumentLoader;
+class WebLocalFrame;
+}
+
+namespace content {
+class RenderFrame;
+}
+
+namespace user_scripts {
+
+// Extensions wrapper for a v8::Context.
+//
+// v8::Contexts can be constructed on any thread, and must only be accessed or
+// destroyed that thread.
+//
+// Note that ScriptContexts bound to worker threads will not have the full
+// functionality as those bound to the main RenderThread.
+class ScriptContext {
+ public:
+  // TODO(devlin): Move all these Get*URL*() methods out of here? While they are
+  // vaguely ScriptContext related, there's enough here that they probably
+  // warrant another class or utility file.
+
+  // Utility to get the URL we will match against for a frame. If the frame has
+  // committed, this is the commited URL. Otherwise it is the provisional URL.
+  // The returned URL may be invalid.
+  static GURL GetDocumentLoaderURLForFrame(const blink::WebLocalFrame* frame);
+
+  // Used to determine the "effective" URL for extension script injection.
+  // If |document_url| is an about: or data: URL, returns the URL of the first
+  // frame without an about: or data: URL that matches the initiator origin.
+  // This may not be the immediate parent. Returns |document_url| if it is not
+  // an about: or data: URL, if |match_origin_as_fallback| is set to not match,
+  // or if a suitable parent cannot be found.
+  // Considers parent contexts that cannot be accessed (as is the case for
+  // sandboxed frames).
+  static GURL GetEffectiveDocumentURLForInjection(
+      blink::WebLocalFrame* frame,
+      const GURL& document_url,
+      MatchOriginAsFallbackBehavior match_origin_as_fallback);
+
+//   DISALLOW_COPY_AND_ASSIGN(ScriptContext);
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_RENDERER_SCRIPT_CONTEXT_H_
diff --git a/components/user_scripts/renderer/script_injection.cc b/components/user_scripts/renderer/script_injection.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/script_injection.cc
@@ -0,0 +1,342 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "script_injection.h"
+
+#include <map>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/feature_list.h"
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/timer/elapsed_timer.h"
+#include "base/values.h"
+#include "base/logging.h"
+#include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/render_frame_observer.h"
+#include "content/public/renderer/v8_value_converter.h"
+#include "../common/host_id.h"
+#include "script_injection_callback.h"
+#include "scripts_run_info.h"
+#include "third_party/blink/public/platform/web_isolated_world_info.h"
+#include "third_party/blink/public/platform/web_security_origin.h"
+#include "third_party/blink/public/platform/web_string.h"
+#include "third_party/blink/public/web/web_document.h"
+#include "third_party/blink/public/web/web_local_frame.h"
+#include "third_party/blink/public/web/web_script_source.h"
+#include "url/gurl.h"
+
+namespace user_scripts {
+
+namespace {
+
+using IsolatedWorldMap = std::map<std::string, int>;
+base::LazyInstance<IsolatedWorldMap>::DestructorAtExit g_isolated_worlds =
+    LAZY_INSTANCE_INITIALIZER;
+
+const int64_t kInvalidRequestId = -1;
+
+// Gets the isolated world ID to use for the given |injection_host|. If no
+// isolated world has been created for that |injection_host| one will be created
+// and initialized.
+int GetIsolatedWorldIdForInstance(const InjectionHost* injection_host) {
+  static int g_next_isolated_world_id = 1; // Embedder isolated worlds can use IDs in [1, 1<<29).
+
+  IsolatedWorldMap& isolated_worlds = g_isolated_worlds.Get();
+
+  int id = 0;
+  const std::string& key = injection_host->id().id();
+  auto iter = isolated_worlds.find(key);
+  if (iter != isolated_worlds.end()) {
+    id = iter->second;
+  } else {
+    id = g_next_isolated_world_id++;
+    // This map will tend to pile up over time, but realistically, you're never
+    // going to have enough injection hosts for it to matter.
+    isolated_worlds[key] = id;
+  }
+
+  blink::WebIsolatedWorldInfo info;
+  info.security_origin =
+      blink::WebSecurityOrigin::Create(injection_host->url());
+  info.human_readable_name = blink::WebString::FromUTF8(injection_host->name());
+  info.stable_id = blink::WebString::FromUTF8(key);
+
+  const std::string* csp = injection_host->GetContentSecurityPolicy();
+  if (csp)
+    info.content_security_policy = blink::WebString::FromUTF8(*csp);
+
+  // Even though there may be an existing world for this |injection_host|'s key,
+  // the properties may have changed (e.g. due to an extension update).
+  // Overwrite any existing entries.
+  blink::SetIsolatedWorldInfo(id, info);
+
+  return id;
+}
+
+// This class manages its own lifetime.
+class TimedScriptInjectionCallback : public ScriptInjectionCallback {
+ public:
+  TimedScriptInjectionCallback(base::WeakPtr<ScriptInjection> injection)
+      : ScriptInjectionCallback(
+            base::Bind(&TimedScriptInjectionCallback::OnCompleted,
+                       base::Unretained(this))),
+        injection_(injection) {}
+  ~TimedScriptInjectionCallback() override {}
+
+  void OnCompleted(const std::vector<v8::Local<v8::Value>>& result) {
+    if (injection_) {
+      base::TimeTicks timestamp(base::TimeTicks::Now());
+      base::Optional<base::TimeDelta> elapsed;
+      // If the script will never execute (such as if the context is destroyed),
+      // willExecute() will not be called, but OnCompleted() will. Only log a
+      // time for execution if the script, in fact, executed.
+      if (!start_time_.is_null())
+        elapsed = timestamp - start_time_;
+      injection_->OnJsInjectionCompleted(result, elapsed);
+    }
+  }
+
+  void WillExecute() override {
+    start_time_ = base::TimeTicks::Now();
+  }
+
+ private:
+  base::WeakPtr<ScriptInjection> injection_;
+  base::TimeTicks start_time_;
+};
+
+}  // namespace
+
+// Watches for the deletion of a RenderFrame, after which is_valid will return
+// false.
+class ScriptInjection::FrameWatcher : public content::RenderFrameObserver {
+ public:
+  FrameWatcher(content::RenderFrame* render_frame,
+               ScriptInjection* injection)
+      : content::RenderFrameObserver(render_frame),
+        injection_(injection) {}
+  ~FrameWatcher() override {}
+
+ private:
+  void WillDetach() override { injection_->invalidate_render_frame(); }
+  void OnDestruct() override { injection_->invalidate_render_frame(); }
+
+  ScriptInjection* injection_;
+
+  DISALLOW_COPY_AND_ASSIGN(FrameWatcher);
+};
+
+// static
+std::string ScriptInjection::GetHostIdForIsolatedWorld(int isolated_world_id) {
+  const IsolatedWorldMap& isolated_worlds = g_isolated_worlds.Get();
+
+  for (const auto& iter : isolated_worlds) {
+    if (iter.second == isolated_world_id)
+      return iter.first;
+  }
+  return std::string();
+}
+
+// static
+void ScriptInjection::RemoveIsolatedWorld(const std::string& host_id) {
+  g_isolated_worlds.Get().erase(host_id);
+}
+
+ScriptInjection::ScriptInjection(
+    std::unique_ptr<ScriptInjector> injector,
+    content::RenderFrame* render_frame,
+    std::unique_ptr<const InjectionHost> injection_host,
+    UserScript::RunLocation run_location,
+    bool log_activity)
+    : injector_(std::move(injector)),
+      render_frame_(render_frame),
+      injection_host_(std::move(injection_host)),
+      run_location_(run_location),
+      request_id_(kInvalidRequestId),
+      complete_(false),
+      did_inject_js_(false),
+      log_activity_(log_activity),
+      frame_watcher_(new FrameWatcher(render_frame, this)) {
+  CHECK(injection_host_.get());
+}
+
+ScriptInjection::~ScriptInjection() {
+  if (!complete_)
+    NotifyWillNotInject(ScriptInjector::WONT_INJECT);
+}
+
+ScriptInjection::InjectionResult ScriptInjection::TryToInject(
+    UserScript::RunLocation current_location,
+    ScriptsRunInfo* scripts_run_info,
+    CompletionCallback async_completion_callback) {
+  if (current_location < run_location_)
+    return INJECTION_WAITING;  // Wait for the right location.
+
+  if (request_id_ != kInvalidRequestId) {
+    // We're waiting for permission right now, try again later.
+    return INJECTION_WAITING;
+  }
+
+  if (!injection_host_) {
+    NotifyWillNotInject(ScriptInjector::EXTENSION_REMOVED);
+    return INJECTION_FINISHED;  // We're done.
+  }
+
+  InjectionResult result = Inject(scripts_run_info);
+  // If the injection is blocked, we need to set the manager so we can
+  // notify it upon completion.
+  if (result == INJECTION_BLOCKED)
+    async_completion_callback_ = std::move(async_completion_callback);
+  return result;
+}
+
+ScriptInjection::InjectionResult ScriptInjection::OnPermissionGranted(
+    ScriptsRunInfo* scripts_run_info) {
+  if (!injection_host_) {
+    NotifyWillNotInject(ScriptInjector::EXTENSION_REMOVED);
+    return INJECTION_FINISHED;
+  }
+
+  return Inject(scripts_run_info);
+}
+
+void ScriptInjection::OnHostRemoved() {
+  injection_host_.reset(nullptr);
+}
+
+void ScriptInjection::NotifyWillNotInject(
+    ScriptInjector::InjectFailureReason reason) {
+  complete_ = true;
+  injector_->OnWillNotInject(reason, render_frame_);
+}
+
+ScriptInjection::InjectionResult ScriptInjection::Inject(
+    ScriptsRunInfo* scripts_run_info) {
+  DCHECK(injection_host_);
+  //DCHECK(scripts_run_info);
+  DCHECK(!complete_);
+  bool should_inject_js = injector_->ShouldInjectJs(
+      run_location_, scripts_run_info->executing_scripts[host_id().id()]);
+  bool should_inject_css = injector_->ShouldInjectCss(
+      run_location_, scripts_run_info->injected_stylesheets[host_id().id()]);
+
+  // This can happen if the extension specified a script to
+  // be run in multiple rules, and the script has already run.
+  // See crbug.com/631247.
+  if (!should_inject_js && !should_inject_css) {
+    return INJECTION_FINISHED;
+  }
+
+  if (should_inject_js)
+    InjectJs(&(scripts_run_info->executing_scripts[host_id().id()]),
+             &(scripts_run_info->num_js));
+  if (should_inject_css)
+    InjectCss(&(scripts_run_info->injected_stylesheets[host_id().id()]),
+              &(scripts_run_info->num_css));
+
+  complete_ = did_inject_js_ || !should_inject_js;
+
+  if (complete_) {
+    injector_->OnInjectionComplete(std::move(execution_result_), run_location_,
+                                   render_frame_);
+  } else {
+    ++scripts_run_info->num_blocking_js;
+  }
+
+  return complete_ ? INJECTION_FINISHED : INJECTION_BLOCKED;
+}
+
+void ScriptInjection::InjectJs(std::set<std::string>* executing_scripts,
+                               size_t* num_injected_js_scripts) {
+  DCHECK(!did_inject_js_);
+  std::vector<blink::WebScriptSource> sources = injector_->GetJsSources(
+      run_location_, executing_scripts, num_injected_js_scripts);
+  DCHECK(!sources.empty());
+  int world_id = GetIsolatedWorldIdForInstance(injection_host_.get());
+  bool is_user_gesture = injector_->IsUserGesture();
+
+  std::unique_ptr<blink::WebScriptExecutionCallback> callback(
+      new TimedScriptInjectionCallback(weak_ptr_factory_.GetWeakPtr()));
+
+  base::ElapsedTimer exec_timer;
+
+  // For content scripts executing during page load, we run them asynchronously
+  // in order to reduce UI jank experienced by the user. (We don't do this for
+  // DOCUMENT_START scripts, because there's no UI to jank until after those
+  // run, so we run them as soon as we can.)
+  // Note: We could potentially also run deferred and browser-driven scripts
+  // asynchronously; however, these are rare enough that there probably isn't
+  // UI jank. If this changes, we can update this.
+  bool should_execute_asynchronously =
+      injector_->script_type() == UserScript::CONTENT_SCRIPT &&
+      (run_location_ == UserScript::DOCUMENT_END ||
+       run_location_ == UserScript::DOCUMENT_IDLE);
+  blink::WebLocalFrame::ScriptExecutionType execution_option =
+      should_execute_asynchronously
+          ? blink::WebLocalFrame::kAsynchronousBlockingOnload
+          : blink::WebLocalFrame::kSynchronous;
+
+  render_frame_->GetWebFrame()->RequestExecuteScriptInIsolatedWorld(
+      world_id, &sources.front(), sources.size(), is_user_gesture,
+      execution_option, callback.release());
+}
+
+void ScriptInjection::OnJsInjectionCompleted(
+    const std::vector<v8::Local<v8::Value>>& results,
+    base::Optional<base::TimeDelta> elapsed) {
+  DCHECK(!did_inject_js_);
+
+  bool expects_results = injector_->ExpectsResults();
+  if (expects_results) {
+    if (!results.empty() && !results[0].IsEmpty()) {
+      // Right now, we only support returning single results (per frame).
+      // It's safe to always use the main world context when converting
+      // here. V8ValueConverterImpl shouldn't actually care about the
+      // context scope, and it switches to v8::Object's creation context
+      // when encountered.
+      v8::Local<v8::Context> context =
+          render_frame_->GetWebFrame()->MainWorldScriptContext();
+      execution_result_ =
+          content::V8ValueConverter::Create()->FromV8Value(results[0], context);
+    }
+    if (!execution_result_.get())
+      execution_result_ = std::make_unique<base::Value>();
+  }
+  did_inject_js_ = true;
+
+  // If |async_completion_callback_| is set, it means the script finished
+  // asynchronously, and we should run it.
+  if (!async_completion_callback_.is_null()) {
+    complete_ = true;
+    injector_->OnInjectionComplete(std::move(execution_result_), run_location_,
+                                   render_frame_);
+    // Warning: this object can be destroyed after this line!
+    std::move(async_completion_callback_).Run(this);
+  }
+}
+
+void ScriptInjection::InjectCss(std::set<std::string>* injected_stylesheets,
+                                size_t* num_injected_stylesheets) {
+  std::vector<blink::WebString> css_sources = injector_->GetCssSources(
+      run_location_, injected_stylesheets, num_injected_stylesheets);
+  blink::WebLocalFrame* web_frame = render_frame_->GetWebFrame();
+  // Default CSS origin is "author", but can be overridden to "user" by scripts.
+  base::Optional<CSSOrigin> css_origin = injector_->GetCssOrigin();
+  blink::WebDocument::CSSOrigin blink_css_origin =
+      css_origin && *css_origin == CSS_ORIGIN_USER
+          ? blink::WebDocument::kUserOrigin
+          : blink::WebDocument::kAuthorOrigin;
+  blink::WebStyleSheetKey style_sheet_key;
+  if (const base::Optional<std::string>& injection_key =
+          injector_->GetInjectionKey())
+    style_sheet_key = blink::WebString::FromASCII(*injection_key);
+  for (const blink::WebString& css : css_sources)
+    web_frame->GetDocument().InsertStyleSheet(css, &style_sheet_key,
+                                              blink_css_origin);
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/renderer/script_injection.h b/components/user_scripts/renderer/script_injection.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/script_injection.h
@@ -0,0 +1,156 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_SCRIPT_INJECTION_H_
+#define USERSCRIPTS_RENDERER_SCRIPT_INJECTION_H_
+
+#include <stdint.h>
+
+#include <memory>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/optional.h"
+#include "../common/user_script.h"
+#include "injection_host.h"
+#include "script_injector.h"
+
+struct HostID;
+
+namespace content {
+class RenderFrame;
+}
+
+namespace v8 {
+class Value;
+template <class T> class Local;
+}
+
+namespace user_scripts {
+struct ScriptsRunInfo;
+
+// A script wrapper which is aware of whether or not it is allowed to execute,
+// and contains the implementation to do so.
+class ScriptInjection {
+ public:
+  enum InjectionResult {
+    INJECTION_FINISHED,
+    INJECTION_BLOCKED,
+    INJECTION_WAITING
+  };
+
+  using CompletionCallback = base::OnceCallback<void(ScriptInjection*)>;
+
+  // Return the id of the injection host associated with the given world.
+  static std::string GetHostIdForIsolatedWorld(int world_id);
+
+  // Remove the isolated world associated with the given injection host.
+  static void RemoveIsolatedWorld(const std::string& host_id);
+
+  ScriptInjection(std::unique_ptr<ScriptInjector> injector,
+                  content::RenderFrame* render_frame,
+                  std::unique_ptr<const InjectionHost> injection_host,
+                  UserScript::RunLocation run_location,
+                  bool log_activity);
+  ~ScriptInjection();
+
+  // Try to inject the script at the |current_location|. This returns
+  // INJECTION_FINISHED if injection has injected or will never inject, returns
+  // INJECTION_BLOCKED if injection is running asynchronously and has not
+  // finished yet, returns INJECTION_WAITING if injections is delayed (either
+  // for permission purposes or because |current_location| is not the designated
+  // |run_location_|).
+  // If INJECTION_BLOCKED is returned, |async_completion_callback| will be
+  // called upon completion.
+  InjectionResult TryToInject(
+      UserScript::RunLocation current_location,
+      ScriptsRunInfo* scripts_run_info,
+      CompletionCallback async_completion_callback);
+
+  // Called when permission for the given injection has been granted.
+  // Returns INJECTION_FINISHED if injection has injected or will never inject,
+  // returns INJECTION_BLOCKED if injection is ran asynchronously.
+  InjectionResult OnPermissionGranted(ScriptsRunInfo* scripts_run_info);
+
+  // Resets the pointer of the injection host when the host is gone.
+  void OnHostRemoved();
+
+  void invalidate_render_frame() { render_frame_ = nullptr; }
+
+  // Accessors.
+  content::RenderFrame* render_frame() const { return render_frame_; }
+  const HostID& host_id() const { return injection_host_->id(); }
+  int64_t request_id() const { return request_id_; }
+
+  // Called when JS injection for the given frame has been completed or
+  // cancelled.
+  void OnJsInjectionCompleted(const std::vector<v8::Local<v8::Value>>& results,
+                              base::Optional<base::TimeDelta> elapsed);
+
+ private:
+  class FrameWatcher;
+
+  // Sends a message to the browser to request permission to inject.
+  void RequestPermissionFromBrowser();
+
+  // Injects the script. Returns INJECTION_FINISHED if injection has finished,
+  // otherwise INJECTION_BLOCKED.
+  InjectionResult Inject(ScriptsRunInfo* scripts_run_info);
+
+  // Inject any JS scripts into the frame for the injection.
+  void InjectJs(std::set<std::string>* executing_scripts,
+                size_t* num_injected_js_scripts);
+
+  // Inject any CSS source into the frame for the injection.
+  void InjectCss(std::set<std::string>* injected_stylesheets,
+                 size_t* num_injected_stylesheets);
+
+  // Notify that we will not inject, and mark it as acknowledged.
+  void NotifyWillNotInject(ScriptInjector::InjectFailureReason reason);
+
+  // The injector for this injection.
+  std::unique_ptr<ScriptInjector> injector_;
+
+  // The RenderFrame into which this should inject the script.
+  content::RenderFrame* render_frame_;
+
+  // The associated injection host.
+  std::unique_ptr<const InjectionHost> injection_host_;
+
+  // The location in the document load at which we inject the script.
+  UserScript::RunLocation run_location_;
+
+  // This injection's request id. This will be -1 unless the injection is
+  // currently waiting on permission.
+  int64_t request_id_;
+
+  // Whether or not the injection is complete, either via injecting the script
+  // or because it will never complete.
+  bool complete_;
+
+  // Whether or not the injection successfully injected JS.
+  bool did_inject_js_;
+
+  // Whether or not we should log dom activity for this injection.
+  bool log_activity_;
+
+  // Results storage.
+  std::unique_ptr<base::Value> execution_result_;
+
+  // The callback to run upon completing asynchronously.
+  CompletionCallback async_completion_callback_;
+
+  // A helper class to hold the render frame and watch for its deletion.
+  std::unique_ptr<FrameWatcher> frame_watcher_;
+
+  base::WeakPtrFactory<ScriptInjection> weak_ptr_factory_{this};
+
+  DISALLOW_COPY_AND_ASSIGN(ScriptInjection);
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_RENDERER_SCRIPT_INJECTION_H_
diff --git a/components/user_scripts/renderer/script_injection_callback.cc b/components/user_scripts/renderer/script_injection_callback.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/script_injection_callback.cc
@@ -0,0 +1,26 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "script_injection_callback.h"
+
+#include "third_party/blink/public/platform/web_vector.h"
+
+namespace user_scripts {
+
+ScriptInjectionCallback::ScriptInjectionCallback(
+    const CompleteCallback& injection_completed_callback)
+    : injection_completed_callback_(injection_completed_callback) {
+}
+
+ScriptInjectionCallback::~ScriptInjectionCallback() {
+}
+
+void ScriptInjectionCallback::Completed(
+    const blink::WebVector<v8::Local<v8::Value>>& result) {
+  std::vector<v8::Local<v8::Value>> stl_result(result.begin(), result.end());
+  injection_completed_callback_.Run(stl_result);
+  delete this;
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/renderer/script_injection_callback.h b/components/user_scripts/renderer/script_injection_callback.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/script_injection_callback.h
@@ -0,0 +1,38 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_SCRIPT_INJECTION_CALLBACK_H_
+#define USERSCRIPTS_RENDERER_SCRIPT_INJECTION_CALLBACK_H_
+
+#include <vector>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "third_party/blink/public/web/web_script_execution_callback.h"
+#include "v8/include/v8.h"
+
+namespace user_scripts {
+
+// A wrapper around a callback to notify a script injection when injection
+// completes.
+// This class manages its own lifetime.
+class ScriptInjectionCallback : public blink::WebScriptExecutionCallback {
+ public:
+  using CompleteCallback =
+      base::Callback<void(const std::vector<v8::Local<v8::Value>>& result)>;
+
+  ScriptInjectionCallback(const CompleteCallback& injection_completed_callback);
+  ~ScriptInjectionCallback() override;
+
+  void Completed(const blink::WebVector<v8::Local<v8::Value>>& result) override;
+
+ private:
+  CompleteCallback injection_completed_callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScriptInjectionCallback);
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_RENDERER_SCRIPT_INJECTION_CALLBACK_H_
diff --git a/components/user_scripts/renderer/script_injection_manager.cc b/components/user_scripts/renderer/script_injection_manager.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/script_injection_manager.cc
@@ -0,0 +1,417 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "script_injection_manager.h"
+
+#include <memory>
+#include <utility>
+
+#include "base/auto_reset.h"
+#include "base/bind.h"
+#include "base/feature_list.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/values.h"
+#include "base/logging.h"
+#include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/render_frame_observer.h"
+#include "content/public/renderer/render_thread.h"
+#include "extension_frame_helper.h"
+#include "../common/host_id.h"
+#include "script_injection.h"
+#include "scripts_run_info.h"
+#include "web_ui_injection_host.h"
+#include "ipc/ipc_message_macros.h"
+#include "third_party/blink/public/platform/web_url_error.h"
+#include "third_party/blink/public/web/web_document.h"
+#include "third_party/blink/public/web/web_frame.h"
+#include "third_party/blink/public/web/web_local_frame.h"
+#include "third_party/blink/public/web/web_view.h"
+#include "url/gurl.h"
+#include "../common/user_scripts_features.h"
+
+namespace user_scripts {
+
+namespace {
+
+// The length of time to wait after the DOM is complete to try and run user
+// scripts.
+const int kScriptIdleTimeoutInMs = 200;
+
+// Returns the RunLocation that follows |run_location|.
+UserScript::RunLocation NextRunLocation(UserScript::RunLocation run_location) {
+  switch (run_location) {
+    case UserScript::DOCUMENT_START:
+      return UserScript::DOCUMENT_END;
+    case UserScript::DOCUMENT_END:
+      return UserScript::DOCUMENT_IDLE;
+    case UserScript::DOCUMENT_IDLE:
+      return UserScript::RUN_LOCATION_LAST;
+    case UserScript::UNDEFINED:
+    case UserScript::RUN_DEFERRED:
+    case UserScript::BROWSER_DRIVEN:
+    case UserScript::RUN_LOCATION_LAST:
+      break;
+  }
+  NOTREACHED();
+  return UserScript::RUN_LOCATION_LAST;
+}
+
+}  // namespace
+
+class ScriptInjectionManager::RFOHelper : public content::RenderFrameObserver {
+ public:
+  RFOHelper(content::RenderFrame* render_frame,
+            ScriptInjectionManager* manager);
+  ~RFOHelper() override;
+
+  // commit @9f2aac4
+  void Initialize();
+
+ private:
+  // RenderFrameObserver implementation.
+  void DidCreateNewDocument() override;
+  void DidCreateDocumentElement() override;
+  void DidFailProvisionalLoad() override;
+  void DidFinishDocumentLoad() override;
+  void WillDetach() override;
+  void OnDestruct() override;
+  void OnStop() override;
+
+  // Tells the ScriptInjectionManager to run tasks associated with
+  // document_idle.
+  void RunIdle();
+
+  void StartInjectScripts(UserScript::RunLocation run_location);
+
+  // Indicate that the frame is no longer valid because it is starting
+  // a new load or closing.
+  void InvalidateAndResetFrame(bool force_reset);
+
+  // The owning ScriptInjectionManager.
+  ScriptInjectionManager* manager_;
+
+  bool should_run_idle_ = true; // commit @9f2aac4
+
+  base::WeakPtrFactory<RFOHelper> weak_factory_{this};
+};
+
+ScriptInjectionManager::RFOHelper::RFOHelper(content::RenderFrame* render_frame,
+                                             ScriptInjectionManager* manager)
+    : content::RenderFrameObserver(render_frame),
+      manager_(manager),
+      should_run_idle_(true) {}
+
+ScriptInjectionManager::RFOHelper::~RFOHelper() {
+}
+
+
+void ScriptInjectionManager::RFOHelper::Initialize() {
+  // Set up for the initial empty document, for which the Document created
+  // events do not happen as it's already present.
+  DidCreateNewDocument();
+  // The initial empty document for a main frame may have scripts attached to it
+  // but we do not want to invalidate the frame and lose them when the next
+  // document loads. For example the IncognitoApiTest.IncognitoSplitMode test
+  // does `chrome.tabs.create()` with a script to be run, which is added to the
+  // frame before it navigates, so it needs to be preserved. However scripts in
+  // child frames are expected to be run inside the initial empty document. For
+  // example the ExecuteScriptApiTest.FrameWithHttp204 test creates a child
+  // frame at about:blank and expects to run injected scripts inside it.
+  // This is all quite inconsistent however tests both depend on us queuing and
+  // not queueing the DOCUMENT_START events in the initial empty document.
+  if (!render_frame()->IsMainFrame()) {
+    DidCreateDocumentElement();
+  }
+}
+
+void ScriptInjectionManager::RFOHelper::DidCreateNewDocument() {
+  // A new document is going to be shown, so invalidate the old document state.
+  // Don't force-reset the frame, because it is possible that a script injection
+  // was scheduled before the page was loaded, e.g. by navigating to a
+  // javascript: URL before the page has loaded.
+  constexpr bool kForceReset = false;
+  InvalidateAndResetFrame(kForceReset);
+}
+
+void ScriptInjectionManager::RFOHelper::DidCreateDocumentElement() {
+  if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+    LOG(INFO) << "UserScripts: DidCreateDocumentElement -> DOCUMENT_START";
+
+  ExtensionFrameHelper::Get(render_frame())
+      ->ScheduleAtDocumentStart(
+          base::BindOnce(&ScriptInjectionManager::RFOHelper::StartInjectScripts,
+                     weak_factory_.GetWeakPtr(), UserScript::DOCUMENT_START));
+}
+
+void ScriptInjectionManager::RFOHelper::DidFailProvisionalLoad() {
+  auto it = manager_->frame_statuses_.find(render_frame());
+  if (it != manager_->frame_statuses_.end() &&
+      it->second == UserScript::DOCUMENT_START) {
+    // Since the provisional load failed, the frame stays at its previous loaded
+    // state and origin (or the parent's origin for new/about:blank frames).
+    // Reset the frame to DOCUMENT_IDLE in order to reflect that the frame is
+    // done loading, and avoid any deadlock in the system.
+    //
+    // We skip injection of DOCUMENT_END and DOCUMENT_IDLE scripts, because the
+    // injections closely follow the DOMContentLoaded (and onload) events, which
+    // are not triggered after a failed provisional load.
+    // This assumption is verified in the checkDOMContentLoadedEvent subtest of
+    // ExecuteScriptApiTest.FrameWithHttp204 (browser_tests).
+    constexpr bool kForceReset = true;
+    InvalidateAndResetFrame(kForceReset);
+    should_run_idle_ = false;
+    manager_->frame_statuses_[render_frame()] = UserScript::DOCUMENT_IDLE;
+  }
+}
+
+void ScriptInjectionManager::RFOHelper::DidFinishDocumentLoad() {
+  if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+    LOG(INFO) << "UserScripts: DidFinishDocumentLoad -> DOCUMENT_END";
+
+  DCHECK(content::RenderThread::Get());
+  ExtensionFrameHelper::Get(render_frame())
+      ->ScheduleAtDocumentEnd(
+          base::BindOnce(&ScriptInjectionManager::RFOHelper::StartInjectScripts,
+                     weak_factory_.GetWeakPtr(), UserScript::DOCUMENT_END));
+
+  // We try to run idle in two places: a delayed task here and in response to
+  // ContentRendererClient::RunScriptsAtDocumentIdle(). DidFinishDocumentLoad()
+  // corresponds to completing the document's load, whereas
+  // RunScriptsAtDocumentIdle() corresponds to completing the document and all
+  // subresources' load (but before the window.onload event). We don't want to
+  // hold up script injection for a particularly slow subresource, so we set a
+  // delayed task from here - but if we finish everything before that point
+  // (i.e., RunScriptsAtDocumentIdle() is triggered), then there's no reason to
+  // keep waiting.
+  render_frame()
+      ->GetTaskRunner(blink::TaskType::kInternalDefault)
+      ->PostDelayedTask(
+          FROM_HERE,
+          base::BindOnce(&ScriptInjectionManager::RFOHelper::RunIdle,
+                         weak_factory_.GetWeakPtr()),
+          base::TimeDelta::FromMilliseconds(kScriptIdleTimeoutInMs));
+
+  ExtensionFrameHelper::Get(render_frame())
+      ->ScheduleAtDocumentIdle(
+          base::BindOnce(&ScriptInjectionManager::RFOHelper::RunIdle,
+                     weak_factory_.GetWeakPtr()));
+}
+
+void ScriptInjectionManager::RFOHelper::WillDetach() {
+  // The frame is closing - invalidate.
+  constexpr bool kForceReset = true;
+  InvalidateAndResetFrame(kForceReset);
+}
+
+void ScriptInjectionManager::RFOHelper::OnDestruct() {
+  manager_->RemoveObserver(this);
+}
+
+void ScriptInjectionManager::RFOHelper::OnStop() {
+  // If the navigation request fails (e.g. 204/205/downloads), notify the
+  // extension to avoid keeping the frame in a START state indefinitely which
+  // leads to deadlocks.
+  DidFailProvisionalLoad();
+}
+
+void ScriptInjectionManager::RFOHelper::RunIdle() {
+  // Only notify the manager if the frame hasn't already had idle run since the
+  // task to RunIdle() was posted.
+  if (should_run_idle_) {
+    should_run_idle_ = false;
+    if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+      LOG(INFO) << "UserScripts: RunIdle -> DOCUMENT_IDLE";
+    manager_->StartInjectScripts(render_frame(), UserScript::DOCUMENT_IDLE);
+  }
+}
+
+void ScriptInjectionManager::RFOHelper::StartInjectScripts(
+    UserScript::RunLocation run_location) {
+  manager_->StartInjectScripts(render_frame(), run_location);
+}
+
+void ScriptInjectionManager::RFOHelper::InvalidateAndResetFrame(
+    bool force_reset) {
+  // Invalidate any pending idle injections, and reset the frame inject on idle.
+  weak_factory_.InvalidateWeakPtrs();
+  // We reset to inject on idle, because the frame can be reused (in the case of
+  // navigation).
+  should_run_idle_ = true;
+
+  // Reset the frame if either |force_reset| is true, or if the manager is
+  // keeping track of the state of the frame (in which case we need to clean it
+  // up).
+  if (force_reset || manager_->frame_statuses_.count(render_frame()) != 0)
+    manager_->InvalidateForFrame(render_frame());
+}
+
+ScriptInjectionManager::ScriptInjectionManager(
+    UserScriptSetManager* user_script_set_manager)
+    : user_script_set_manager_(user_script_set_manager),
+      user_script_set_manager_observer_(this) {
+  user_script_set_manager_observer_.Add(user_script_set_manager_);
+}
+
+ScriptInjectionManager::~ScriptInjectionManager() {
+  for (const auto& injection : pending_injections_)
+    injection->invalidate_render_frame();
+  for (const auto& injection : running_injections_)
+    injection->invalidate_render_frame();
+}
+
+void ScriptInjectionManager::OnRenderFrameCreated(
+    content::RenderFrame* render_frame) {
+  rfo_helpers_.push_back(std::make_unique<RFOHelper>(render_frame, this));
+  rfo_helpers_.back()->Initialize(); // commit @9f2aac4
+}
+
+void ScriptInjectionManager::OnInjectionFinished(
+    ScriptInjection* injection) {
+  auto iter =
+      std::find_if(running_injections_.begin(), running_injections_.end(),
+                   [injection](const std::unique_ptr<ScriptInjection>& mode) {
+                     return injection == mode.get();
+                   });
+  if (iter != running_injections_.end())
+    running_injections_.erase(iter);
+}
+
+void ScriptInjectionManager::OnUserScriptsUpdated(
+    const std::set<HostID>& changed_hosts) {
+  for (auto iter = pending_injections_.begin();
+       iter != pending_injections_.end();) {
+    if (changed_hosts.count((*iter)->host_id()) > 0)
+      iter = pending_injections_.erase(iter);
+    else
+      ++iter;
+  }
+}
+
+void ScriptInjectionManager::RemoveObserver(RFOHelper* helper) {
+  for (auto iter = rfo_helpers_.begin(); iter != rfo_helpers_.end(); ++iter) {
+    if (iter->get() == helper) {
+      rfo_helpers_.erase(iter);
+      break;
+    }
+  }
+}
+
+void ScriptInjectionManager::InvalidateForFrame(content::RenderFrame* frame) {
+  // If the frame invalidated is the frame being injected into, we need to
+  // note it.
+  active_injection_frames_.erase(frame);
+
+  for (auto iter = pending_injections_.begin();
+       iter != pending_injections_.end();) {
+    if ((*iter)->render_frame() == frame)
+      iter = pending_injections_.erase(iter);
+    else
+      ++iter;
+  }
+
+  frame_statuses_.erase(frame);
+}
+
+void ScriptInjectionManager::StartInjectScripts(
+    content::RenderFrame* frame,
+    UserScript::RunLocation run_location) {
+  auto iter = frame_statuses_.find(frame);
+  // We also don't execute if we detect that the run location is somehow out of
+  // order. This can happen if:
+  // - The first run location reported for the frame isn't DOCUMENT_START, or
+  // - The run location reported doesn't immediately follow the previous
+  //   reported run location.
+  // We don't want to run because extensions may have requirements that scripts
+  // running in an earlier run location have run by the time a later script
+  // runs. Better to just not run.
+  // Note that we check run_location > NextRunLocation() in the second clause
+  // (as opposed to !=) because earlier signals (like DidCreateDocumentElement)
+  // can happen multiple times, so we can receive earlier/equal run locations.
+  if ((iter == frame_statuses_.end() &&
+           run_location != UserScript::DOCUMENT_START) ||
+      (iter != frame_statuses_.end() &&
+           run_location > NextRunLocation(iter->second))) {
+    // We also invalidate the frame, because the run order of pending injections
+    // may also be bad.
+    InvalidateForFrame(frame);
+    return;
+  } else if (iter != frame_statuses_.end() && iter->second >= run_location) {
+    // Certain run location signals (like DidCreateDocumentElement) can happen
+    // multiple times. Ignore the subsequent signals.
+    return;
+  }
+
+  // Otherwise, all is right in the world, and we can get on with the
+  // injections!
+  frame_statuses_[frame] = run_location;
+  InjectScripts(frame, run_location);
+}
+
+void ScriptInjectionManager::InjectScripts(
+    content::RenderFrame* frame,
+    UserScript::RunLocation run_location) {
+  // Find any injections that want to run on the given frame.
+  ScriptInjectionVector frame_injections;
+  for (auto iter = pending_injections_.begin();
+       iter != pending_injections_.end();) {
+    if ((*iter)->render_frame() == frame) {
+      frame_injections.push_back(std::move(*iter));
+      iter = pending_injections_.erase(iter);
+    } else {
+      ++iter;
+    }
+  }
+
+  // Add any injections for user scripts.
+  int tab_id = ExtensionFrameHelper::Get(frame)->tab_id();
+  user_script_set_manager_->GetAllInjections(&frame_injections, frame, tab_id,
+                                             run_location);
+
+  // Note that we are running in |frame|.
+  active_injection_frames_.insert(frame);
+
+  ScriptsRunInfo scripts_run_info(frame, run_location);
+
+  for (auto iter = frame_injections.begin(); iter != frame_injections.end();) {
+    // It's possible for thScriptsRunInfoe frame to be invalidated in the course of injection
+    // (if a script removes its own frame, for example). If this happens, abort.
+    if (!active_injection_frames_.count(frame))
+      break;
+    std::unique_ptr<ScriptInjection> injection(std::move(*iter));
+    iter = frame_injections.erase(iter);
+    TryToInject(std::move(injection), run_location, &scripts_run_info);
+  }
+
+  // We are done running in the frame.
+  active_injection_frames_.erase(frame);
+
+  scripts_run_info.LogRun(activity_logging_enabled_);
+}
+
+void ScriptInjectionManager::TryToInject(
+    std::unique_ptr<ScriptInjection> injection,
+    UserScript::RunLocation run_location,
+    ScriptsRunInfo* scripts_run_info) {
+  // Try to inject the script. If the injection is waiting (i.e., for
+  // permission), add it to the list of pending injections. If the injection
+  // has blocked, add it to the list of running injections.
+  // The Unretained below is safe because this object owns all the
+  // ScriptInjections, so is guaranteed to outlive them.
+  switch (injection->TryToInject(
+      run_location, scripts_run_info,
+      base::Bind(&ScriptInjectionManager::OnInjectionFinished,
+                 base::Unretained(this)))) {
+    case ScriptInjection::INJECTION_WAITING:
+      pending_injections_.push_back(std::move(injection));
+      break;
+    case ScriptInjection::INJECTION_BLOCKED:
+      running_injections_.push_back(std::move(injection));
+      break;
+    case ScriptInjection::INJECTION_FINISHED:
+      break;
+  }
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/renderer/script_injection_manager.h b/components/user_scripts/renderer/script_injection_manager.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/script_injection_manager.h
@@ -0,0 +1,102 @@
+#include <stdint.h>
+
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/macros.h"
+#include "base/scoped_observer.h"
+#include "../common/user_script.h"
+#include "script_injection.h"
+#include "user_script_set_manager.h"
+
+namespace user_scripts {
+
+// The ScriptInjectionManager manages extensions injecting scripts into frames
+// via both content/user scripts and tabs.executeScript(). It is responsible for
+// maintaining any pending injections awaiting permission or the appropriate
+// load point, and injecting them when ready.
+class ScriptInjectionManager : public UserScriptSetManager::Observer {
+ public:
+  explicit ScriptInjectionManager(
+      UserScriptSetManager* user_script_set_manager);
+  virtual ~ScriptInjectionManager();
+
+  // Notifies that a new render view has been created.
+  void OnRenderFrameCreated(content::RenderFrame* render_frame);
+
+  // Removes pending injections of the unloaded extension.
+  //void OnExtensionUnloaded(const std::string& extension_id);
+
+  void set_activity_logging_enabled(bool enabled) {
+    activity_logging_enabled_ = enabled;
+  }
+
+ private:
+  // A RenderFrameObserver implementation which watches the various render
+  // frames in order to notify the ScriptInjectionManager of different
+  // document load states and IPCs.
+  class RFOHelper;
+
+  using FrameStatusMap =
+      std::map<content::RenderFrame*, UserScript::RunLocation>;
+
+  using ScriptInjectionVector = std::vector<std::unique_ptr<ScriptInjection>>;
+
+  // Notifies that an injection has been finished.
+  void OnInjectionFinished(ScriptInjection* injection);
+
+  // UserScriptSetManager::Observer implementation.
+  void OnUserScriptsUpdated(const std::set<HostID>& changed_hosts) override;
+
+  // Notifies that an RFOHelper should be removed.
+  void RemoveObserver(RFOHelper* helper);
+
+  // Invalidate any pending tasks associated with |frame|.
+  void InvalidateForFrame(content::RenderFrame* frame);
+
+  // Starts the process to inject appropriate scripts into |frame|.
+  void StartInjectScripts(content::RenderFrame* frame,
+                          UserScript::RunLocation run_location);
+
+  // Actually injects the scripts into |frame|.
+  void InjectScripts(content::RenderFrame* frame,
+                     UserScript::RunLocation run_location);
+
+  // Try to inject and store injection if it has not finished.
+  void TryToInject(std::unique_ptr<ScriptInjection> injection,
+                   UserScript::RunLocation run_location,
+                   ScriptsRunInfo* scripts_run_info);
+
+  // The map of active web frames to their corresponding statuses. The
+  // RunLocation of the frame corresponds to the last location that has ran.
+  FrameStatusMap frame_statuses_;
+
+  // The frames currently being injected into, so long as that frame is valid.
+  std::set<content::RenderFrame*> active_injection_frames_;
+
+  // The collection of RFOHelpers.
+  std::vector<std::unique_ptr<RFOHelper>> rfo_helpers_;
+
+  // The set of UserScripts associated with extensions. Owned by the Dispatcher.
+  UserScriptSetManager* user_script_set_manager_;
+
+  // Pending injections which are waiting for either the proper run location or
+  // user consent.
+  ScriptInjectionVector pending_injections_;
+
+  // Running injections which are waiting for async callbacks from blink.
+  ScriptInjectionVector running_injections_;
+
+  // Whether or not dom activity should be logged for scripts injected.
+  bool activity_logging_enabled_ = false;
+
+  ScopedObserver<UserScriptSetManager, UserScriptSetManager::Observer>
+      user_script_set_manager_observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScriptInjectionManager);
+};
+
+}
diff --git a/components/user_scripts/renderer/script_injector.h b/components/user_scripts/renderer/script_injector.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/script_injector.h
@@ -0,0 +1,96 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_SCRIPT_INJECTOR_H_
+#define USERSCRIPTS_RENDERER_SCRIPT_INJECTOR_H_
+
+#include <memory>
+#include <vector>
+
+#include "../common/constants.h"
+#include "../common/user_script.h"
+#include "third_party/blink/public/web/web_script_source.h"
+
+class InjectionHost;
+
+namespace blink {
+class WebLocalFrame;
+}
+
+namespace user_scripts {
+
+// The pseudo-delegate class for a ScriptInjection that provides all necessary
+// information about how to inject the script, including what code to inject and
+// when (run location), but without any injection logic.
+class ScriptInjector {
+ public:
+  // The possible reasons for not injecting the script.
+  enum InjectFailureReason {
+    EXTENSION_REMOVED,  // The extension was removed before injection.
+    NOT_ALLOWED,        // The script is not allowed to inject.
+    WONT_INJECT         // The injection won't inject because the user rejected
+                        // (or just did not accept) the injection.
+  };
+
+  virtual ~ScriptInjector() {}
+
+  // Returns the script type of this particular injection.
+  virtual UserScript::InjectionType script_type() const = 0;
+
+  // Returns true if the script is running inside a user gesture.
+  virtual bool IsUserGesture() const = 0;
+
+  // Returns the CSS origin of this injection.
+  virtual base::Optional<CSSOrigin> GetCssOrigin() const = 0;
+
+  // Returns the key for this injection, if it's a CSS injection.
+  virtual const base::Optional<std::string> GetInjectionKey() const = 0;
+
+  // Returns true if the script expects results.
+  virtual bool ExpectsResults() const = 0;
+
+  // Returns true if the script should inject JS source at the given
+  // |run_location|.
+  virtual bool ShouldInjectJs(
+      UserScript::RunLocation run_location,
+      const std::set<std::string>& executing_scripts) const = 0;
+
+  // Returns true if the script should inject CSS at the given |run_location|.
+  virtual bool ShouldInjectCss(
+      UserScript::RunLocation run_location,
+      const std::set<std::string>& injected_stylesheets) const = 0;
+
+  // Returns the javascript sources to inject at the given |run_location|.
+  // Only called if ShouldInjectJs() is true.
+  virtual std::vector<blink::WebScriptSource> GetJsSources(
+      UserScript::RunLocation run_location,
+      std::set<std::string>* executing_scripts,
+      size_t* num_injected_js_scripts) const = 0;
+
+  // Returns the css to inject at the given |run_location|.
+  // Only called if ShouldInjectCss() is true.
+  virtual std::vector<blink::WebString> GetCssSources(
+      UserScript::RunLocation run_location,
+      std::set<std::string>* injected_stylesheets,
+      size_t* num_injected_stylesheets) const = 0;
+
+  // Notifies the script that injection has completed, with a possibly-populated
+  // list of results (depending on whether or not ExpectsResults() was true).
+  // |render_frame| contains the render frame, or null if the frame was
+  // invalidated.
+  virtual void OnInjectionComplete(
+      std::unique_ptr<base::Value> execution_result,
+      UserScript::RunLocation run_location,
+      content::RenderFrame* render_frame) = 0;
+
+  // Notifies the script that injection will never occur.
+  // |render_frame| contains the render frame, or null if the frame was
+  // invalidated.
+  virtual void OnWillNotInject(InjectFailureReason reason,
+                               content::RenderFrame* render_frame) = 0;
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_RENDERER_SCRIPT_INJECTOR_H_
diff --git a/components/user_scripts/renderer/scripts_run_info.cc b/components/user_scripts/renderer/scripts_run_info.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/scripts_run_info.cc
@@ -0,0 +1,31 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "scripts_run_info.h"
+
+#include "base/metrics/histogram_macros.h"
+#include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/render_thread.h"
+#include "script_context.h"
+#include "third_party/blink/public/web/web_local_frame.h"
+
+namespace user_scripts {
+
+ScriptsRunInfo::ScriptsRunInfo(content::RenderFrame* render_frame,
+                               UserScript::RunLocation location)
+    : num_css(0u),
+      num_js(0u),
+      num_blocking_js(0u),
+      routing_id_(render_frame->GetRoutingID()),
+      run_location_(location),
+      frame_url_(ScriptContext::GetDocumentLoaderURLForFrame(
+          render_frame->GetWebFrame())) {}
+
+ScriptsRunInfo::~ScriptsRunInfo() {
+}
+
+void ScriptsRunInfo::LogRun(bool send_script_activity) {
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/renderer/scripts_run_info.h b/components/user_scripts/renderer/scripts_run_info.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/scripts_run_info.h
@@ -0,0 +1,70 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_SCRIPTS_RUN_INFO_H_
+#define USERSCRIPTS_RENDERER_SCRIPTS_RUN_INFO_H_
+
+#include <stddef.h>
+
+#include <map>
+#include <set>
+#include <string>
+
+#include "base/macros.h"
+#include "base/timer/elapsed_timer.h"
+#include "../common/user_script.h"
+
+namespace content {
+class RenderFrame;
+}
+
+namespace user_scripts {
+
+// A struct containing information about a script run.
+struct ScriptsRunInfo {
+  // Map of extensions IDs to the executing script paths.
+  typedef std::map<std::string, std::set<std::string> > ExecutingScriptsMap;
+
+  ScriptsRunInfo(content::RenderFrame* render_frame,
+                 UserScript::RunLocation location);
+  ~ScriptsRunInfo();
+
+  // The number of CSS scripts injected.
+  size_t num_css;
+  // The number of JS scripts injected.
+  size_t num_js;
+  // The number of blocked JS scripts injected.
+  size_t num_blocking_js;
+  // A map of extension ids to executing script paths.
+  ExecutingScriptsMap executing_scripts;
+  // A map of extension ids to injected stylesheet paths.
+  ExecutingScriptsMap injected_stylesheets;
+  // The elapsed time since the ScriptsRunInfo was constructed.
+  base::ElapsedTimer timer;
+
+  // Log information about a given script run. If |send_script_activity| is
+  // true, this also informs the browser of the script run.
+  void LogRun(bool send_script_activity);
+
+  static void LogLongInjectionTaskTime(UserScript::RunLocation run_location,
+                                       const base::TimeDelta& elapsed);
+
+ private:
+  // The routinig id to use to notify the browser of any injections. Since the
+  // frame may be deleted in injection, we don't hold on to a reference to it
+  // directly.
+  int routing_id_;
+
+  // The run location at which injection is happening.
+  UserScript::RunLocation run_location_;
+
+  // The url of the frame, preserved for the same reason as the routing id.
+  GURL frame_url_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScriptsRunInfo);
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_RENDERER_SCRIPTS_RUN_INFO_H_
diff --git a/components/user_scripts/renderer/user_script_injector.cc b/components/user_scripts/renderer/user_script_injector.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_script_injector.cc
@@ -0,0 +1,228 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "user_script_injector.h"
+
+#include <tuple>
+#include <vector>
+
+#include "base/logging.h"
+#include "base/lazy_instance.h"
+#include "content/public/common/url_constants.h"
+#include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/render_thread.h"
+#include "content/public/renderer/render_view.h"
+#include "components/user_scripts/renderer/grit/user_scripts_renderer_resources.h"
+#include "injection_host.h"
+#include "script_context.h"
+#include "scripts_run_info.h"
+#include "third_party/blink/public/web/web_document.h"
+#include "third_party/blink/public/web/web_local_frame.h"
+#include "third_party/blink/public/web/web_script_source.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "url/gurl.h"
+
+namespace user_scripts {
+
+namespace {
+
+struct RoutingInfoKey {
+  int routing_id;
+  int script_id;
+
+  RoutingInfoKey(int routing_id, int script_id)
+      : routing_id(routing_id), script_id(script_id) {}
+
+  bool operator<(const RoutingInfoKey& other) const {
+    return std::tie(routing_id, script_id) <
+           std::tie(other.routing_id, other.script_id);
+  }
+};
+
+using RoutingInfoMap = std::map<RoutingInfoKey, bool>;
+
+// A map records whether a given |script_id| from a webview-added user script
+// is allowed to inject on the render of given |routing_id|.
+// Once a script is added, the decision of whether or not allowed to inject
+// won't be changed.
+// After removed by the webview, the user scipt will also be removed
+// from the render. Therefore, there won't be any query from the same
+// |script_id| and |routing_id| pair.
+// base::LazyInstance<RoutingInfoMap>::DestructorAtExit g_routing_info_map =
+//    LAZY_INSTANCE_INITIALIZER;
+
+// Greasemonkey API source that is injected with the scripts.
+struct GreasemonkeyApiJsString {
+  GreasemonkeyApiJsString();
+  blink::WebScriptSource GetSource() const;
+
+ private:
+  blink::WebString source_;
+};
+
+// The below constructor, monstrous as it is, just makes a WebScriptSource from
+// the GreasemonkeyApiJs resource.
+GreasemonkeyApiJsString::GreasemonkeyApiJsString() {
+  std::string greasemonky_api_js(
+      ui::ResourceBundle::GetSharedInstance().LoadDataResourceString(
+          IDR_GREASEMONKEY_API_JS));
+  source_ = blink::WebString::FromUTF8(greasemonky_api_js);
+}
+
+blink::WebScriptSource GreasemonkeyApiJsString::GetSource() const {
+  return blink::WebScriptSource(source_);
+}
+
+base::LazyInstance<GreasemonkeyApiJsString>::Leaky g_greasemonkey_api =
+    LAZY_INSTANCE_INITIALIZER;
+
+bool ShouldInjectScripts(const UserScript::FileList& scripts,
+                         const std::set<std::string>& injected_files) {
+  for (const std::unique_ptr<UserScript::File>& file : scripts) {
+    // Check if the script is already injected.
+    if (injected_files.count(file->url().path()) == 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
+}  // namespace
+
+UserScriptInjector::UserScriptInjector(const UserScript* script,
+                                       UserScriptSet* script_list)
+    : script_(script),
+      user_script_set_(script_list),
+      script_id_(script_->id()),
+      user_script_set_observer_(this) {
+  user_script_set_observer_.Add(script_list);
+}
+
+UserScriptInjector::~UserScriptInjector() {
+}
+
+void UserScriptInjector::OnUserScriptsUpdated(
+    const std::set<HostID>& changed_hosts,
+    const UserScriptList& scripts) {
+  // When user scripts are updated, all the old script pointers are invalidated.
+  script_ = nullptr;
+  // If the host causing this injection changed, then this injection
+  // will be removed, and there's no guarantee the backing script still exists.
+  // if (changed_hosts.count(host_id_) > 0)
+  //   return;
+
+  for (const std::unique_ptr<UserScript>& script : scripts) {
+    if (script->id() == script_id_) {
+      script_ = script.get();
+      break;
+    }
+  }
+  // If |host_id_| wasn't in |changed_hosts|, then the script for this injection
+  // should be guaranteed to exist.
+  DCHECK(script_);
+}
+
+UserScript::InjectionType UserScriptInjector::script_type() const {
+  return UserScript::CONTENT_SCRIPT;
+}
+
+bool UserScriptInjector::IsUserGesture() const {
+  return false;
+}
+
+bool UserScriptInjector::ExpectsResults() const {
+  return false;
+}
+
+base::Optional<CSSOrigin> UserScriptInjector::GetCssOrigin() const {
+  return base::nullopt;
+}
+
+const base::Optional<std::string> UserScriptInjector::GetInjectionKey() const {
+  return base::nullopt;
+}
+
+bool UserScriptInjector::ShouldInjectJs(
+    UserScript::RunLocation run_location,
+    const std::set<std::string>& executing_scripts) const {
+  return script_ && script_->run_location() == run_location &&
+         !script_->js_scripts().empty() &&
+         ShouldInjectScripts(script_->js_scripts(), executing_scripts);
+}
+
+bool UserScriptInjector::ShouldInjectCss(
+    UserScript::RunLocation run_location,
+    const std::set<std::string>& injected_stylesheets) const {
+  return script_ && run_location == UserScript::DOCUMENT_START &&
+         !script_->css_scripts().empty() &&
+         ShouldInjectScripts(script_->css_scripts(), injected_stylesheets);
+}
+
+std::vector<blink::WebScriptSource> UserScriptInjector::GetJsSources(
+    UserScript::RunLocation run_location,
+    std::set<std::string>* executing_scripts,
+    size_t* num_injected_js_scripts) const {
+  DCHECK(script_);
+  std::vector<blink::WebScriptSource> sources;
+
+  DCHECK_EQ(script_->run_location(), run_location);
+
+  const UserScript::FileList& js_scripts = script_->js_scripts();
+  sources.reserve(js_scripts.size() +
+                  (script_->emulate_greasemonkey() ? 1 : 0));
+  // Emulate Greasemonkey API for scripts that were converted to extension
+  // user scripts.
+  if (script_->emulate_greasemonkey())
+    sources.push_back(g_greasemonkey_api.Get().GetSource());
+  for (const std::unique_ptr<UserScript::File>& file : js_scripts) {
+    const GURL& script_url = file->url();
+    // Check if the script is already injected.
+    if (executing_scripts->count(script_url.path()) != 0)
+      continue;
+
+    sources.push_back(blink::WebScriptSource(
+        user_script_set_->GetJsSource(*file, script_->emulate_greasemonkey()),
+        script_url));
+
+    (*num_injected_js_scripts) += 1;
+    executing_scripts->insert(script_url.path());
+  }
+
+  return sources;
+}
+
+std::vector<blink::WebString> UserScriptInjector::GetCssSources(
+    UserScript::RunLocation run_location,
+    std::set<std::string>* injected_stylesheets,
+    size_t* num_injected_stylesheets) const {
+  DCHECK(script_);
+  DCHECK_EQ(UserScript::DOCUMENT_START, run_location);
+
+  std::vector<blink::WebString> sources;
+
+  const UserScript::FileList& css_scripts = script_->css_scripts();
+  sources.reserve(css_scripts.size());
+  for (const std::unique_ptr<UserScript::File>& file : script_->css_scripts()) {
+    const std::string& stylesheet_path = file->url().path();
+    // Check if the stylesheet is already injected.
+    if (injected_stylesheets->count(stylesheet_path) != 0)
+      continue;
+
+    sources.push_back(user_script_set_->GetCssSource(*file));
+    (*num_injected_stylesheets) += 1;
+    injected_stylesheets->insert(stylesheet_path);
+  }
+  return sources;
+}
+
+void UserScriptInjector::OnInjectionComplete(
+    std::unique_ptr<base::Value> execution_result,
+    UserScript::RunLocation run_location,
+    content::RenderFrame* render_frame) {}
+
+void UserScriptInjector::OnWillNotInject(InjectFailureReason reason,
+                                         content::RenderFrame* render_frame) {
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/renderer/user_script_injector.h b/components/user_scripts/renderer/user_script_injector.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_script_injector.h
@@ -0,0 +1,86 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_USER_SCRIPT_INJECTOR_H_
+#define USERSCRIPTS_RENDERER_USER_SCRIPT_INJECTOR_H_
+
+#include <memory>
+#include <string>
+
+#include "base/macros.h"
+#include "base/scoped_observer.h"
+#include "../common/user_script.h"
+#include "script_injection.h"
+#include "user_script_set.h"
+
+class InjectionHost;
+
+namespace blink {
+class WebLocalFrame;
+}
+
+namespace user_scripts {
+
+// A ScriptInjector for UserScripts.
+class UserScriptInjector : public ScriptInjector,
+                           public UserScriptSet::Observer {
+ public:
+  UserScriptInjector(const UserScript* user_script,
+                     UserScriptSet* user_script_set);
+  ~UserScriptInjector() override;
+
+ private:
+  // UserScriptSet::Observer implementation.
+  void OnUserScriptsUpdated(const std::set<HostID>& changed_hosts,
+                            const UserScriptList& scripts) override;
+
+  // ScriptInjector implementation.
+  UserScript::InjectionType script_type() const override;
+  bool IsUserGesture() const override;
+  base::Optional<CSSOrigin> GetCssOrigin() const override;
+  const base::Optional<std::string> GetInjectionKey() const override;
+  bool ExpectsResults() const override;
+  bool ShouldInjectJs(
+      UserScript::RunLocation run_location,
+      const std::set<std::string>& executing_scripts) const override;
+  bool ShouldInjectCss(
+      UserScript::RunLocation run_location,
+      const std::set<std::string>& injected_stylesheets) const override;
+  std::vector<blink::WebScriptSource> GetJsSources(
+      UserScript::RunLocation run_location,
+      std::set<std::string>* executing_scripts,
+      size_t* num_injected_js_scripts) const override;
+  std::vector<blink::WebString> GetCssSources(
+      UserScript::RunLocation run_location,
+      std::set<std::string>* injected_stylesheets,
+      size_t* num_injected_stylesheets) const override;
+  void OnInjectionComplete(std::unique_ptr<base::Value> execution_result,
+                           UserScript::RunLocation run_location,
+                           content::RenderFrame* render_frame) override;
+  void OnWillNotInject(InjectFailureReason reason,
+                       content::RenderFrame* render_frame) override;
+
+  // The associated user script. Owned by the UserScriptInjector that created
+  // this object.
+  const UserScript* script_;
+
+  // The UserScriptSet that eventually owns the UserScript this
+  // UserScriptInjector points to.
+  // Outlives |this|.
+  UserScriptSet* const user_script_set_;
+
+  // The id of the associated user script. We cache this because when we update
+  // the |script_| associated with this injection, the old referance may be
+  // deleted.
+  int script_id_;
+
+  ScopedObserver<UserScriptSet, UserScriptSet::Observer>
+      user_script_set_observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserScriptInjector);
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_RENDERER_USER_SCRIPT_INJECTOR_H_
diff --git a/components/user_scripts/renderer/user_script_set.cc b/components/user_scripts/renderer/user_script_set.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_script_set.cc
@@ -0,0 +1,258 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "user_script_set.h"
+
+#include <stddef.h>
+
+#include <utility>
+
+#include "base/logging.h"
+#include "base/debug/alias.h"
+#include "base/memory/ref_counted.h"
+#include "base/strings/strcat.h"
+#include "content/public/common/url_constants.h"
+#include "content/public/renderer/render_frame.h"
+#include "content/public/renderer/render_thread.h"
+#include "injection_host.h"
+#include "script_context.h"
+#include "script_injection.h"
+#include "user_script_injector.h"
+#include "web_ui_injection_host.h"
+#include "third_party/blink/public/web/web_document.h"
+#include "third_party/blink/public/web/web_local_frame.h"
+#include "url/gurl.h"
+#include "../common/user_scripts_features.h"
+
+namespace user_scripts {
+
+namespace {
+
+// These two strings are injected before and after the Greasemonkey API and
+// user script to wrap it in an anonymous scope.
+const char kUserScriptHead[] = "(function (unsafeWindow) {\n";
+const char kUserScriptTail[] = "\n})(window);";
+// Maximum number of total content scripts we allow (across all extensions).
+// The limit exists to diagnose https://crbug.com/723381. The number is
+// arbitrarily chosen.
+// TODO(lazyboy): Remove when the bug is fixed.
+const uint32_t kNumScriptsArbitraryMax = 100000u;
+
+GURL GetDocumentUrlForFrame(blink::WebLocalFrame* frame) {
+  GURL data_source_url = ScriptContext::GetDocumentLoaderURLForFrame(frame);
+  if (!data_source_url.is_empty() && frame->IsViewSourceModeEnabled()) {
+    data_source_url = GURL(content::kViewSourceScheme + std::string(":") +
+                           data_source_url.spec());
+  }
+
+  return data_source_url;
+}
+
+}  // namespace
+
+UserScriptSet::UserScriptSet() {}
+
+UserScriptSet::~UserScriptSet() {
+}
+
+void UserScriptSet::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void UserScriptSet::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void UserScriptSet::GetInjections(
+    std::vector<std::unique_ptr<ScriptInjection>>* injections,
+    content::RenderFrame* render_frame,
+    int tab_id,
+    UserScript::RunLocation run_location,
+    bool log_activity) {
+  GURL document_url = GetDocumentUrlForFrame(render_frame->GetWebFrame());
+  for (const std::unique_ptr<UserScript>& script : scripts_) {
+    std::unique_ptr<ScriptInjection> injection = GetInjectionForScript(
+        script.get(), render_frame, tab_id, run_location, document_url,
+        /* is_declarative, */ log_activity);
+    if (injection.get())
+      injections->push_back(std::move(injection));
+  }
+}
+
+bool UserScriptSet::UpdateUserScripts(
+    base::ReadOnlySharedMemoryRegion shared_memory,
+    const std::set<HostID>& changed_hosts,
+    bool whitelisted_only) {
+  bool only_inject_incognito = false;
+  //ExtensionsRendererClient::Get()->IsIncognitoProcess();
+
+  // Create the shared memory mapping.
+  shared_memory_mapping_ = shared_memory.Map();
+  if (!shared_memory.IsValid())
+    return false;
+
+  // First get the size of the memory block.
+  const base::Pickle::Header* pickle_header =
+      shared_memory_mapping_.GetMemoryAs<base::Pickle::Header>();
+  if (!pickle_header)
+    return false;
+
+  // Now read in the rest of the block.
+  size_t pickle_size =
+      sizeof(base::Pickle::Header) + pickle_header->payload_size;
+
+  // Unpickle scripts.
+  uint32_t num_scripts = 0;
+  auto memory = shared_memory_mapping_.GetMemoryAsSpan<char>(pickle_size);
+  if (!memory.size())
+    return false;
+
+  base::Pickle pickle(memory.data(), pickle_size);
+  base::PickleIterator iter(pickle);
+  base::debug::Alias(&pickle_size);
+  CHECK(iter.ReadUInt32(&num_scripts));
+
+  // Sometimes the shared memory contents seem to be corrupted
+  // (https://crbug.com/723381). Set an arbitrary max limit to the number of
+  // scripts so that we don't add OOM noise to crash reports.
+  CHECK_LT(num_scripts, kNumScriptsArbitraryMax);
+
+  scripts_.clear();
+  script_sources_.clear();
+  scripts_.reserve(num_scripts);
+  for (uint32_t i = 0; i < num_scripts; ++i) {
+    std::unique_ptr<UserScript> script(new UserScript());
+    script->Unpickle(pickle, &iter);
+
+    // Note that this is a pointer into shared memory. We don't own it. It gets
+    // cleared up when the last renderer or browser process drops their
+    // reference to the shared memory.
+    for (size_t j = 0; j < script->js_scripts().size(); ++j) {
+      const char* body = NULL;
+      int body_length = 0;
+      CHECK(iter.ReadData(&body, &body_length));
+      script->js_scripts()[j]->set_external_content(
+          base::StringPiece(body, body_length));
+    }
+    for (size_t j = 0; j < script->css_scripts().size(); ++j) {
+      const char* body = NULL;
+      int body_length = 0;
+      CHECK(iter.ReadData(&body, &body_length));
+      script->css_scripts()[j]->set_external_content(
+          base::StringPiece(body, body_length));
+    }
+
+    if (only_inject_incognito && !script->is_incognito_enabled())
+      continue;  // This script shouldn't run in an incognito tab.
+
+    scripts_.push_back(std::move(script));
+  }
+
+  for (auto& observer : observers_)
+    observer.OnUserScriptsUpdated(changed_hosts, scripts_);
+  return true;
+}
+
+void UserScriptSet::AddScript(std::unique_ptr<UserScript> script) {
+  scripts_.push_back(std::move(script));
+}
+
+std::unique_ptr<ScriptInjection> UserScriptSet::GetInjectionForScript(
+    const UserScript* script,
+    content::RenderFrame* render_frame,
+    int tab_id,
+    UserScript::RunLocation run_location,
+    const GURL& document_url,
+    //bool is_declarative,
+    bool log_activity) {
+  std::unique_ptr<ScriptInjection> injection;
+  std::unique_ptr<const InjectionHost> injection_host;
+  blink::WebLocalFrame* web_frame = render_frame->GetWebFrame();
+
+  const HostID& host_id = script->host_id();
+  injection_host.reset(new WebUIInjectionHost(host_id));
+
+  GURL effective_document_url =
+      ScriptContext::GetEffectiveDocumentURLForInjection(
+          web_frame, document_url, script->match_origin_as_fallback());
+
+  bool is_subframe = web_frame->Parent();
+  if (!script->MatchesDocument(effective_document_url, is_subframe)) {
+    if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+      LOG(INFO) << "UserScripts: No Match name=" << script->name() << " " <<
+                                         "url=" << effective_document_url.spec();
+    return injection;
+  }
+
+  std::unique_ptr<ScriptInjector> injector(
+      new UserScriptInjector(script, this));
+
+  bool inject_css = !script->css_scripts().empty() &&
+                    run_location == UserScript::DOCUMENT_START;
+  bool inject_js =
+      !script->js_scripts().empty() && script->run_location() == run_location;
+  if (inject_css || inject_js) {
+    injection.reset(new ScriptInjection(std::move(injector), render_frame,
+                                        std::move(injection_host), run_location,
+                                        log_activity));
+    if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+      LOG(INFO) << "UserScripts: Match name=" << script->name() << " " <<
+                                         "url=" << effective_document_url.spec();
+  } else {
+    if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts)) {
+      if (script->run_location() != run_location)
+        LOG(INFO) << "UserScripts: wrong run location current " << run_location << " " <<
+                                                     "expeted " << script->run_location();
+      else
+        LOG(INFO) << "UserScripts: Match but no script name=" << script->name() << " " <<
+                                          "url=" << effective_document_url.spec();
+    }
+  }
+  return injection;
+}
+
+blink::WebString UserScriptSet::GetJsSource(const UserScript::File& file,
+                                            bool emulate_greasemonkey) {
+  const GURL& url = file.url();
+  auto iter = script_sources_.find(url);
+  if (iter != script_sources_.end()) {
+    return iter->second;
+  }
+
+  base::StringPiece script_content = file.GetContent();
+  blink::WebString source;
+  if (emulate_greasemonkey) {
+    // We add this dumb function wrapper for user scripts to emulate what
+    // Greasemonkey does. |script_content| becomes:
+    // concat(kUserScriptHead, script_content, kUserScriptTail).
+    std::string content =
+        base::StrCat({kUserScriptHead, script_content, kUserScriptTail});
+    source = blink::WebString::FromUTF8(content);
+    if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+      LOG(INFO) << "UserScripts: Injecting w/greasemonkey " << file.url();
+  } else {
+    source = blink::WebString::FromUTF8(script_content.data(),
+                                        script_content.length());
+    if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+      LOG(INFO) << "UserScripts: Injecting " << file.url();
+  }
+  script_sources_[url] = source;
+  return source;
+}
+
+blink::WebString UserScriptSet::GetCssSource(const UserScript::File& file) {
+  const GURL& url = file.url();
+  auto iter = script_sources_.find(url);
+  if (iter != script_sources_.end())
+    return iter->second;
+
+  base::StringPiece script_content = file.GetContent();
+  return script_sources_
+      .insert(std::make_pair(
+          url, blink::WebString::FromUTF8(script_content.data(),
+                                          script_content.length())))
+      .first->second;
+}
+
+}  // namespace extensions
diff --git a/components/user_scripts/renderer/user_script_set.h b/components/user_scripts/renderer/user_script_set.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_script_set.h
@@ -0,0 +1,102 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_USER_SCRIPT_SET_H_
+#define USERSCRIPTS_RENDERER_USER_SCRIPT_SET_H_
+
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/read_only_shared_memory_region.h"
+#include "base/observer_list.h"
+#include "../common/user_script.h"
+#include "third_party/blink/public/platform/web_string.h"
+
+class GURL;
+
+namespace content {
+class RenderFrame;
+}
+
+namespace user_scripts {
+class ScriptInjection;
+
+// The UserScriptSet is a collection of UserScripts which knows how to update
+// itself from SharedMemory and create ScriptInjections for UserScripts to
+// inject on a page.
+class UserScriptSet {
+ public:
+  class Observer {
+   public:
+    // Called when the set of user scripts is updated. |changed_hosts| contains
+    // the hosts whose scripts have been altered. Note that *all* script objects
+    // are invalidated, even if they aren't in |changed_hosts|.
+    virtual void OnUserScriptsUpdated(const std::set<HostID>& changed_hosts,
+                                      const UserScriptList& scripts) = 0;
+  };
+
+  UserScriptSet();
+  ~UserScriptSet();
+
+  // Adds or removes observers.
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+  void AddScript(std::unique_ptr<UserScript> script);
+
+  // Append any ScriptInjections that should run on the given |render_frame| and
+  // |tab_id|, at the given |run_location|, to |injections|.
+  // |extensions| is passed in to verify the corresponding extension is still
+  // valid.
+  void GetInjections(std::vector<std::unique_ptr<ScriptInjection>>* injections,
+                     content::RenderFrame* render_frame,
+                     int tab_id,
+                     UserScript::RunLocation run_location,
+                     bool log_activity);
+
+  // Updates scripts given the shared memory region containing user scripts.
+  // Returns true if the scripts were successfully updated.
+  bool UpdateUserScripts(base::ReadOnlySharedMemoryRegion shared_memory,
+                         const std::set<HostID>& changed_hosts,
+                         bool whitelisted_only);
+
+  // Returns the contents of a script file.
+  // Note that copying is cheap as this uses WebString.
+  blink::WebString GetJsSource(const UserScript::File& file,
+                               bool emulate_greasemonkey);
+  blink::WebString GetCssSource(const UserScript::File& file);
+
+ private:
+  // Returns a new ScriptInjection for the given |script| to execute in the
+  // |render_frame|, or NULL if the script should not execute.
+  std::unique_ptr<ScriptInjection> GetInjectionForScript(
+      const UserScript* script,
+      content::RenderFrame* render_frame,
+      int tab_id,
+      UserScript::RunLocation run_location,
+      const GURL& document_url,
+      //bool is_declarative,
+      bool log_activity);
+
+  // Shared memory mapping containing raw script data.
+  base::ReadOnlySharedMemoryMapping shared_memory_mapping_;
+
+  // The UserScripts this injector manages.
+  UserScriptList scripts_;
+
+  // Map of user script file url -> source.
+  std::map<GURL, blink::WebString> script_sources_;
+
+  // The associated observers.
+  base::ObserverList<Observer>::Unchecked observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserScriptSet);
+};
+
+}  // namespace extensions
+
+#endif  // USERSCRIPTS_RENDERER_USER_SCRIPT_SET_H_
diff --git a/components/user_scripts/renderer/user_script_set_manager.cc b/components/user_scripts/renderer/user_script_set_manager.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_script_set_manager.cc
@@ -0,0 +1,77 @@
+#include "user_script_set_manager.h"
+
+#include "base/logging.h"
+#include "content/public/renderer/render_thread.h"
+#include "../common/host_id.h"
+#include "../common/extension_messages.h"
+#include "../common/user_scripts_features.h"
+#include "user_script_set.h"
+
+namespace user_scripts {
+
+UserScriptSetManager::UserScriptSetManager() {
+  content::RenderThread::Get()->AddObserver(this);
+}
+
+UserScriptSetManager::~UserScriptSetManager() {
+}
+
+void UserScriptSetManager::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void UserScriptSetManager::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+bool UserScriptSetManager::OnControlMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(UserScriptSetManager, message)
+    IPC_MESSAGE_HANDLER(ExtensionMsg_UpdateUserScripts, OnUpdateUserScripts)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void UserScriptSetManager::GetAllInjections(
+    std::vector<std::unique_ptr<ScriptInjection>>* injections,
+    content::RenderFrame* render_frame,
+    int tab_id,
+    UserScript::RunLocation run_location) {
+
+  if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+    LOG(INFO) << "UserScripts: GetAllInjections";
+
+  // static_scripts_ is UserScriptSet
+  static_scripts_.GetInjections(injections, render_frame, tab_id, run_location,
+                                activity_logging_enabled_);
+}
+
+void UserScriptSetManager::OnUpdateUserScripts(
+    base::ReadOnlySharedMemoryRegion shared_memory) {
+  if (!shared_memory.IsValid()) {
+    NOTREACHED() << "Bad scripts handle";
+    return;
+  }
+
+  UserScriptSet* scripts = NULL;
+  scripts = &static_scripts_;
+
+  DCHECK(scripts);
+
+  // If no hosts are included in the set, that indicates that all
+  // hosts were updated. Add them all to the set so that observers and
+  // individual UserScriptSets don't need to know this detail.
+  //const std::set<HostID>* effective_hosts = &changed_hosts;
+  std::set<HostID> all_hosts;
+  const std::set<HostID>* effective_hosts = &all_hosts;
+
+  if (scripts->UpdateUserScripts(std::move(shared_memory), *effective_hosts,
+                                 false /*whitelisted_only*/)) {
+    for (auto& observer : observers_)
+      observer.OnUserScriptsUpdated(all_hosts /* *effective_hosts*/);
+  }
+}
+
+}
\ No newline at end of file
diff --git a/components/user_scripts/renderer/user_script_set_manager.h b/components/user_scripts/renderer/user_script_set_manager.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_script_set_manager.h
@@ -0,0 +1,62 @@
+#ifndef USERSCRIPTS_RENDER_SET_MANAGER_H_
+#define USERSCRIPTS_RENDER_SET_MANAGER_H_
+
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/read_only_shared_memory_region.h"
+#include "base/observer_list.h"
+#include "content/public/renderer/render_thread_observer.h"
+#include "../common/host_id.h"
+#include "user_script_set.h"
+#include "script_injection.h"
+
+namespace user_scripts {
+
+class UserScriptSetManager : public content::RenderThreadObserver {
+ public:
+  class Observer {
+   public:
+    virtual void OnUserScriptsUpdated(const std::set<HostID>& changed_hosts) = 0;
+  };
+
+  UserScriptSetManager();
+
+  ~UserScriptSetManager() override;
+
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  // Append all injections from |static_scripts| and each of
+  // |programmatic_scripts_| to |injections|.
+  void GetAllInjections(
+      std::vector<std::unique_ptr<ScriptInjection>>* injections,
+      content::RenderFrame* render_frame,
+      int tab_id,
+      UserScript::RunLocation run_location);
+
+private:
+  // content::RenderThreadObserver implementation.
+  bool OnControlMessageReceived(const IPC::Message& message) override;
+
+  base::ObserverList<Observer>::Unchecked observers_;
+
+  // Handle the UpdateUserScripts extension message.
+  void OnUpdateUserScripts(base::ReadOnlySharedMemoryRegion shared_memory);
+                           //, const HostID& host_id,
+                           //const std::set<HostID>& changed_hosts,
+                           //bool whitelisted_only);
+
+  // Scripts statically defined in extension manifests.
+  UserScriptSet static_scripts_;
+
+  // Whether or not dom activity should be logged for scripts injected.
+  bool activity_logging_enabled_ = false;
+};
+
+}
+
+#endif
\ No newline at end of file
diff --git a/components/user_scripts/renderer/user_scripts_dispatcher.cc b/components/user_scripts/renderer/user_scripts_dispatcher.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_scripts_dispatcher.cc
@@ -0,0 +1,36 @@
+#include "user_scripts_dispatcher.h"
+
+#include <stddef.h>
+
+#include <algorithm>
+#include <memory>
+#include <utility>
+
+#include "content/public/renderer/render_thread.h"
+#include "extension_frame_helper.h"
+
+namespace user_scripts {
+
+// ex ChromeExtensionsDispatcherDelegate
+UserScriptsDispatcher::UserScriptsDispatcher()
+    : user_script_set_manager_observer_(this) {
+      user_script_set_manager_.reset(new UserScriptSetManager());
+      script_injection_manager_.reset(
+          new ScriptInjectionManager(user_script_set_manager_.get()));
+      user_script_set_manager_observer_.Add(user_script_set_manager_.get());
+}
+
+UserScriptsDispatcher::~UserScriptsDispatcher() {
+}
+
+void UserScriptsDispatcher::OnRenderThreadStarted(content::RenderThread* thread) {
+}
+
+void UserScriptsDispatcher::OnUserScriptsUpdated(const std::set<HostID>& changed_hosts) {
+}
+
+void UserScriptsDispatcher::OnRenderFrameCreated(content::RenderFrame* render_frame) {
+  script_injection_manager_->OnRenderFrameCreated(render_frame);
+}
+
+}
\ No newline at end of file
diff --git a/components/user_scripts/renderer/user_scripts_dispatcher.h b/components/user_scripts/renderer/user_scripts_dispatcher.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_scripts_dispatcher.h
@@ -0,0 +1,48 @@
+#ifndef USERSCRIPTS_RENDER_DISPATCHER_H_
+#define USERSCRIPTS_RENDER_DISPATCHER_H_
+
+#include "user_script_set_manager.h"
+#include "script_injection_manager.h"
+
+#include <stdint.h>
+
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/scoped_observer.h"
+#include "content/public/renderer/render_thread_observer.h"
+#include "content/public/renderer/render_thread.h"
+#include "../common/host_id.h"
+#include "user_script_set_manager.h"
+#include "script_injection.h"
+
+namespace user_scripts {
+
+class UserScriptsDispatcher : public content::RenderThreadObserver,
+                              public UserScriptSetManager::Observer {
+
+ public:
+  explicit UserScriptsDispatcher();
+  ~UserScriptsDispatcher() override;
+
+  void OnRenderThreadStarted(content::RenderThread* thread);
+  void OnUserScriptsUpdated(const std::set<HostID>& changed_hosts) override;
+  void OnRenderFrameCreated(content::RenderFrame* render_frame);
+
+ private:
+  std::unique_ptr<UserScriptSetManager> user_script_set_manager_;
+
+  std::unique_ptr<ScriptInjectionManager> script_injection_manager_;
+
+  ScopedObserver<UserScriptSetManager, UserScriptSetManager::Observer>
+      user_script_set_manager_observer_;
+};
+
+}
+
+#endif
\ No newline at end of file
diff --git a/components/user_scripts/renderer/user_scripts_renderer_client.cc b/components/user_scripts/renderer/user_scripts_renderer_client.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_scripts_renderer_client.cc
@@ -0,0 +1,76 @@
+#include "user_scripts_renderer_client.h"
+
+#include <memory>
+#include <utility>
+
+#include "base/logging.h"
+#include "base/lazy_instance.h"
+#include "content/public/renderer/render_thread.h"
+
+#include "../common/user_scripts_features.h"
+#include "user_scripts_dispatcher.h"
+#include "extension_frame_helper.h"
+
+namespace user_scripts {
+
+// was ChromeExtensionsRendererClient
+UserScriptsRendererClient::UserScriptsRendererClient() {}
+
+UserScriptsRendererClient::~UserScriptsRendererClient() {}
+
+// static
+UserScriptsRendererClient* UserScriptsRendererClient::GetInstance() {
+  if (base::FeatureList::IsEnabled(features::kEnableUserScripts) == false)
+    return NULL;
+
+  static base::LazyInstance<UserScriptsRendererClient>::Leaky client =
+      LAZY_INSTANCE_INITIALIZER;
+  return client.Pointer();
+}
+
+void UserScriptsRendererClient::RenderThreadStarted() {
+  if (base::FeatureList::IsEnabled(features::kEnableLoggingUserScripts))
+    LOG(INFO) << "UserScripts: RenderThreadStarted";
+  content::RenderThread* thread = content::RenderThread::Get();
+
+  dispatcher_ = std::make_unique<UserScriptsDispatcher>();
+
+  dispatcher_->OnRenderThreadStarted(thread);
+  thread->AddObserver(dispatcher_.get());
+}
+
+void UserScriptsRendererClient::RenderFrameCreated(
+    content::RenderFrame* render_frame,
+    service_manager::BinderRegistry* registry) {
+  new user_scripts::ExtensionFrameHelper(render_frame);
+  dispatcher_->OnRenderFrameCreated(render_frame);
+}
+
+void UserScriptsRendererClient::RunScriptsAtDocumentStart(content::RenderFrame* render_frame) {
+  ExtensionFrameHelper* frame_helper = ExtensionFrameHelper::Get(render_frame);
+  if (!frame_helper)
+    return;  // The frame is invisible to extensions.
+
+  frame_helper->RunScriptsAtDocumentStart();
+  // |frame_helper| and |render_frame| might be dead by now.
+}
+
+void UserScriptsRendererClient::RunScriptsAtDocumentEnd(content::RenderFrame* render_frame) {
+  ExtensionFrameHelper* frame_helper = ExtensionFrameHelper::Get(render_frame);
+  if (!frame_helper)
+    return;  // The frame is invisible to extensions.
+
+  frame_helper->RunScriptsAtDocumentEnd();
+  // |frame_helper| and |render_frame| might be dead by now.
+}
+
+void UserScriptsRendererClient::RunScriptsAtDocumentIdle(content::RenderFrame* render_frame) {
+  ExtensionFrameHelper* frame_helper = ExtensionFrameHelper::Get(render_frame);
+  if (!frame_helper)
+    return;  // The frame is invisible to extensions.
+
+  frame_helper->RunScriptsAtDocumentIdle();
+  // |frame_helper| and |render_frame| might be dead by now.
+}
+
+}
\ No newline at end of file
diff --git a/components/user_scripts/renderer/user_scripts_renderer_client.h b/components/user_scripts/renderer/user_scripts_renderer_client.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/user_scripts_renderer_client.h
@@ -0,0 +1,33 @@
+#ifndef USERSCRIPTS_RENDER_CLIENT_H_
+#define USERSCRIPTS_RENDER_CLIENT_H_
+
+#include <memory>
+#include <string>
+
+#include "base/macros.h"
+#include "user_scripts_dispatcher.h"
+#include "services/service_manager/public/cpp/binder_registry.h"
+
+namespace user_scripts {
+
+class UserScriptsRendererClient {
+ public:
+  UserScriptsRendererClient();
+  ~UserScriptsRendererClient();
+
+  static UserScriptsRendererClient* GetInstance();
+
+  void RenderThreadStarted();
+  void RenderFrameCreated(content::RenderFrame* render_frame,
+    service_manager::BinderRegistry* registry);
+  void RunScriptsAtDocumentStart(content::RenderFrame* render_frame);
+  void RunScriptsAtDocumentEnd(content::RenderFrame* render_frame);
+  void RunScriptsAtDocumentIdle(content::RenderFrame* render_frame);
+
+ private:
+  std::unique_ptr<UserScriptsDispatcher> dispatcher_;
+};
+
+}
+
+#endif
\ No newline at end of file
diff --git a/components/user_scripts/renderer/web_ui_injection_host.cc b/components/user_scripts/renderer/web_ui_injection_host.cc
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/web_ui_injection_host.cc
@@ -0,0 +1,40 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "web_ui_injection_host.h"
+#include "base/no_destructor.h"
+
+namespace {
+
+// The default secure CSP to be used in order to prevent remote scripts.
+const char kDefaultSecureCSP[] = "script-src 'self'; object-src 'self';";
+
+}
+
+WebUIInjectionHost::WebUIInjectionHost(const HostID& host_id)
+  : InjectionHost(host_id),
+    url_(host_id.id()) {
+}
+
+WebUIInjectionHost::~WebUIInjectionHost() {
+}
+
+const std::string* WebUIInjectionHost::GetContentSecurityPolicy() const {
+  // Use the main world CSP.
+  // return nullptr;
+
+  // The isolated world will use its own CSP which blocks remotely hosted
+  // code.
+  static const base::NoDestructor<std::string> default_isolated_world_csp(
+      kDefaultSecureCSP);
+  return default_isolated_world_csp.get();
+}
+
+const GURL& WebUIInjectionHost::url() const {
+  return url_;
+}
+
+const std::string& WebUIInjectionHost::name() const {
+  return id().id();
+}
diff --git a/components/user_scripts/renderer/web_ui_injection_host.h b/components/user_scripts/renderer/web_ui_injection_host.h
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/renderer/web_ui_injection_host.h
@@ -0,0 +1,28 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef USERSCRIPTS_RENDERER_WEB_UI_INJECTION_HOST_H_
+#define USERSCRIPTS_RENDERER_WEB_UI_INJECTION_HOST_H_
+
+#include "base/macros.h"
+#include "injection_host.h"
+
+class WebUIInjectionHost : public InjectionHost {
+ public:
+  WebUIInjectionHost(const HostID& host_id);
+  ~WebUIInjectionHost() override;
+
+ private:
+  // InjectionHost:
+  const std::string* GetContentSecurityPolicy() const override;
+  const GURL& url() const override;
+  const std::string& name() const override;
+
+ private:
+  GURL url_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebUIInjectionHost);
+};
+
+#endif  // USERSCRIPTS_RENDERER_WEB_UI_INJECTION_HOST_H_
diff --git a/components/user_scripts/strings/userscripts_strings.grdp b/components/user_scripts/strings/userscripts_strings.grdp
new file mode 100755
--- /dev/null
+++ b/components/user_scripts/strings/userscripts_strings.grdp
@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="utf-8"?>
+<grit-part>
+
+  <!-- Preferences -->
+  <message name="IDS_PREFS_USERSCRIPTS_SETTINGS"
+           desc="Title of the dialog that presents a request for payment for some good or service. Sentence-cased."
+           formatter_data="android_java">
+    User Scripts
+  </message>
+
+  <message name="IDS_OPTION_USERSCRIPT_FLAG" desc="." formatter_data="android_java">
+    Activate User Scripts
+  </message>
+
+  <message name="IDS_SCRIPTS_DISABLED_DESCRIPTION" desc="." formatter_data="android_java">
+    Experimental support for userscripts are currently disabled. You can enable them by going to chrome://flags.
+  </message>
+
+  <message name="IDS_OPTION_USERSCRIPT_FLAG_ON" desc=". [CHAR-LIMIT=32]" formatter_data="android_java">
+    ON
+  </message>
+  <message name="IDS_OPTION_USERSCRIPT_FLAG_OFF" desc=". [CHAR-LIMIT=32]" formatter_data="android_java">
+    OFF
+  </message>
+
+  <message name="IDS_ADD_SCRIPT" desc=". [CHAR-LIMIT=32]" formatter_data="android_java">
+    Add script
+  </message>
+  <message name="IDS_SCRIPTS_LIST_DESCRIPTION" desc="." formatter_data="android_java">
+    Experimental support for Greasemonkey-style user scripts. Use at your own risk.
+  </message>
+
+  <message name="IDS_SCRIPTS_VIEW_SOURCE" desc=". [CHAR-LIMIT=32]" formatter_data="android_java">
+    View source
+  </message>
+  <message name="IDS_SCRIPTS_OPEN_URL" desc=". [CHAR-LIMIT=32]" formatter_data="android_java">
+    Open Url
+  </message>
+
+  <message name="IDS_ASK_TO_INSTALL" desc=". [CHAR-LIMIT=32]" formatter_data="android_java">
+    Do you want to install
+  </message>
+  <message name="IDS_YES" desc=". [CHAR-LIMIT=32]" formatter_data="android_java">
+    Yes
+  </message>
+  <message name="IDS_NO" desc=". [CHAR-LIMIT=32]" formatter_data="android_java">
+    No
+  </message>
+
+</grit-part>
\ No newline at end of file
diff --git a/tools/gritsettings/resource_ids.spec b/tools/gritsettings/resource_ids.spec
--- a/tools/gritsettings/resource_ids.spec
+++ b/tools/gritsettings/resource_ids.spec
@@ -464,6 +464,12 @@
   "components/autofill/core/browser/autofill_address_rewriter_resources.grd":{
     "includes": [2880]
   },
+  "components/user_scripts/renderer/resources/user_scripts_renderer_resources.grd": {
+    "includes": [6000],
+  },
+  "components/user_scripts/browser/resources/browser_resources.grd": {
+    "includes": [6020],
+  },
   # END components/ section.
 
   # START ios/ section.
-- 
2.17.1