LibWeb: Introduce the 'ShadowRealmGlobalScope' interface

This object represents the global object for a shadow realm. The IDL
generator will need to be adjusted to the '[Global]' extended attribute
and no '[Exposed]' field (the change in the test is not correct, as I
understand it), but this should be enough to get us started on
shadow realms.

Tests/LibWeb/Text/expected/all-window-properties.txt

@@ -338,6 +338,7 @@ ServiceWorkerContainer
 ServiceWorkerRegistration
 Set
 ShadowRealm
+ShadowRealmGlobalScope
 ShadowRoot
 SharedArrayBuffer
 SourceBuffer

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -462,6 +462,7 @@ set(SOURCES
     HTML/ServiceWorkerRegistration.cpp
     HTML/SessionHistoryEntry.cpp
     HTML/SessionHistoryTraversalQueue.cpp
+    HTML/ShadowRealmGlobalScope.cpp
     HTML/SharedResourceRequest.cpp
     HTML/SourceSet.cpp
     HTML/Storage.cpp

Userland/Libraries/LibWeb/HTML/ShadowRealmGlobalScope.cpp

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2024, Shannon Booth <shannon@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/Bindings/ShadowRealmGlobalScopePrototype.h>
+#include <LibWeb/HTML/ShadowRealmGlobalScope.h>
+
+namespace Web::HTML {
+
+JS_DEFINE_ALLOCATOR(ShadowRealmGlobalScope);
+
+ShadowRealmGlobalScope::ShadowRealmGlobalScope(JS::Realm& realm)
+    : DOM::EventTarget(realm)
+{
+}
+
+ShadowRealmGlobalScope::~ShadowRealmGlobalScope() = default;
+
+JS::NonnullGCPtr<ShadowRealmGlobalScope> ShadowRealmGlobalScope::create(JS::Realm& realm)
+{
+    return realm.heap().allocate<ShadowRealmGlobalScope>(realm, realm);
+}
+
+void ShadowRealmGlobalScope::initialize(JS::Realm&)
+{
+    // FIXME: This does not work as we do not have any intrinsics in the [HostDefined] of a shadow realm. Figure out how this _should_ work.
+    // Base::initialize(realm);
+    // WEB_SET_PROTOTYPE_FOR_INTERFACE(ShadowRealmGlobalScope);
+}
+
+void ShadowRealmGlobalScope::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+}
+
+}

Userland/Libraries/LibWeb/HTML/ShadowRealmGlobalScope.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2024, Shannon Booth <shannon@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/DOM/EventTarget.h>
+
+namespace Web::HTML {
+
+// https://whatpr.org/html/9893/webappapis.html#shadowrealmglobalscope
+class ShadowRealmGlobalScope : public DOM::EventTarget {
+    WEB_PLATFORM_OBJECT(ShadowRealmGlobalScope, DOM::EventTarget);
+    JS_DECLARE_ALLOCATOR(ShadowRealmGlobalScope);
+
+public:
+    virtual ~ShadowRealmGlobalScope() override;
+
+    static JS::NonnullGCPtr<ShadowRealmGlobalScope> create(JS::Realm&);
+
+    // https://whatpr.org/html/9893/webappapis.html#dom-shadowrealmglobalscope-self
+    JS::NonnullGCPtr<ShadowRealmGlobalScope> self()
+    {
+        // The self getter steps are to return this.
+        return *this;
+    }
+
+protected:
+    explicit ShadowRealmGlobalScope(JS::Realm&);
+
+    virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Cell::Visitor&) override;
+};
+
+}

Userland/Libraries/LibWeb/HTML/ShadowRealmGlobalScope.idl

@@ -0,0 +1,6 @@
+// https://whatpr.org/html/9893/webappapis.html#shadowrealmglobalscope
+// FIXME: This is not correct! We should not have Exposed=Window here.
+[Global, Exposed=Window]
+interface ShadowRealmGlobalScope : EventTarget {
+    readonly attribute ShadowRealmGlobalScope self;
+};

Userland/Libraries/LibWeb/idl_files.cmake

@@ -222,6 +222,7 @@ libweb_js_bindings(HTML/RadioNodeList)
 libweb_js_bindings(HTML/ServiceWorker)
 libweb_js_bindings(HTML/ServiceWorkerContainer)
 libweb_js_bindings(HTML/ServiceWorkerRegistration)
+libweb_js_bindings(HTML/ShadowRealmGlobalScope)
 libweb_js_bindings(HTML/Storage)
 libweb_js_bindings(HTML/SubmitEvent)
 libweb_js_bindings(HTML/TextMetrics)