LibWebView+UI: Remove history traversal WebView callbacks

We can handle these entirely within LibWebView.

Ladybird/AppKit/UI/LadybirdWebView.mm

@@ -554,30 +554,6 @@ static void copy_data_to_clipboard(StringView data, NSPasteboardType pasteboard_
         [self updateViewportRect:Ladybird::WebViewBridge::ForResize::Yes];
     };
 
-    m_web_view_bridge->on_navigate_back = [weak_self]() {
-        LadybirdWebView* self = weak_self;
-        if (self == nil) {
-            return;
-        }
-        [self navigateBack];
-    };
-
-    m_web_view_bridge->on_navigate_forward = [weak_self]() {
-        LadybirdWebView* self = weak_self;
-        if (self == nil) {
-            return;
-        }
-        [self navigateForward];
-    };
-
-    m_web_view_bridge->on_refresh = [weak_self]() {
-        LadybirdWebView* self = weak_self;
-        if (self == nil) {
-            return;
-        }
-        [self reload];
-    };
-
     m_web_view_bridge->on_request_tooltip_override = [weak_self](auto, auto const& tooltip) {
         LadybirdWebView* self = weak_self;
         if (self == nil) {

Ladybird/Qt/Tab.cpp

@@ -330,18 +330,6 @@ Tab::Tab(BrowserWindow* window, RefPtr<WebView::WebContentClient> parent_client,
         view().request_style_sheet_source(identifier);
     };
 
-    view().on_navigate_back = [this]() {
-        back();
-    };
-
-    view().on_navigate_forward = [this]() {
-        forward();
-    };
-
-    view().on_refresh = [this]() {
-        reload();
-    };
-
     view().on_restore_window = [this]() {
         m_window->showNormal();
     };

Ladybird/Qt/WebContentView.cpp

@@ -431,13 +431,10 @@ void WebContentView::mouseReleaseEvent(QMouseEvent* event)
 {
     enqueue_native_event(Web::MouseEvent::Type::MouseUp, *event);
 
-    if (event->button() == Qt::MouseButton::BackButton) {
-        if (on_navigate_back)
-            on_navigate_back();
-    } else if (event->button() == Qt::MouseButton::ForwardButton) {
-        if (on_navigate_forward)
-            on_navigate_forward();
-    }
+    if (event->button() == Qt::MouseButton::BackButton)
+        traverse_the_history_by_delta(-1);
+    else if (event->button() == Qt::MouseButton::ForwardButton)
+        traverse_the_history_by_delta(1);
 }
 
 void WebContentView::wheelEvent(QWheelEvent* event)

Userland/Libraries/LibWebView/ViewImplementation.h

@@ -171,9 +171,6 @@ public:
     Function<void(URL::URL const&, bool)> on_load_start;
     Function<void(URL::URL const&)> on_load_finish;
     Function<void(ByteString const& path, i32)> on_request_file;
-    Function<void()> on_navigate_back;
-    Function<void()> on_navigate_forward;
-    Function<void()> on_refresh;
     Function<void(Gfx::Bitmap const&)> on_favicon_change;
     Function<void(Gfx::StandardCursor)> on_cursor_change;
     Function<void(Gfx::IntPoint, ByteString const&)> on_request_tooltip_override;

Userland/Libraries/LibWebView/WebContentClient.cpp

@@ -102,26 +102,20 @@ void WebContentClient::did_find_in_page(u64 page_id, size_t current_match_index,
 
 void WebContentClient::did_request_navigate_back(u64 page_id)
 {
-    if (auto view = view_for_page_id(page_id); view.has_value()) {
-        if (view->on_navigate_back)
-            view->on_navigate_back();
-    }
+    if (auto view = view_for_page_id(page_id); view.has_value())
+        view->traverse_the_history_by_delta(-1);
 }
 
 void WebContentClient::did_request_navigate_forward(u64 page_id)
 {
-    if (auto view = view_for_page_id(page_id); view.has_value()) {
-        if (view->on_navigate_forward)
-            view->on_navigate_forward();
-    }
+    if (auto view = view_for_page_id(page_id); view.has_value())
+        view->traverse_the_history_by_delta(1);
 }
 
 void WebContentClient::did_request_refresh(u64 page_id)
 {
-    if (auto view = view_for_page_id(page_id); view.has_value()) {
-        if (view->on_refresh)
-            view->on_refresh();
-    }
+    if (auto view = view_for_page_id(page_id); view.has_value())
+        view->reload();
 }
 
 void WebContentClient::did_request_cursor_change(u64 page_id, i32 cursor_type)