fix: remove cyclic references of BrowserWindow (#22006)

* fix: remove cyclic references in BrowserWindow

* fix: prevent TopLevelWindow from garbage collection

* test: garbage collection of BrowserWindow

* chore: createIDWeakMap is used in tests

shell/browser/api/electron_api_browser_window.cc

@@ -222,6 +222,31 @@ void BrowserWindow::OnDraggableRegionsUpdated(
   UpdateDraggableRegions(regions);
 }
 
+void BrowserWindow::OnSetContentBounds(const gfx::Rect& rect) {
+  // window.resizeTo(...)
+  // window.moveTo(...)
+  window()->SetBounds(rect, false);
+}
+
+void BrowserWindow::OnActivateContents() {
+  // Hide the auto-hide menu when webContents is focused.
+#if !defined(OS_MACOSX)
+  if (IsMenuBarAutoHide() && IsMenuBarVisible())
+    window()->SetMenuBarVisibility(false);
+#endif
+}
+
+void BrowserWindow::OnPageTitleUpdated(const base::string16& title,
+                                       bool explicit_set) {
+  // Change window title to page title.
+  auto self = GetWeakPtr();
+  if (!Emit("page-title-updated", title, explicit_set)) {
+    // |this| might be deleted, or marked as destroyed by close().
+    if (self && !IsDestroyed())
+      SetTitle(base::UTF16ToUTF8(title));
+  }
+}
+
 void BrowserWindow::RequestPreferredWidth(int* width) {
   *width = web_contents()->GetPreferredSize().width();
 }
@@ -251,6 +276,8 @@ void BrowserWindow::OnCloseButtonClicked(bool* prevent_default) {
 
 void BrowserWindow::OnWindowClosed() {
   Cleanup();
+  // See TopLevelWindow::OnWindowClosed on why calling InvalidateWeakPtrs.
+  weak_factory_.InvalidateWeakPtrs();
   TopLevelWindow::OnWindowClosed();
 }
 

shell/browser/api/electron_api_browser_window.h

@@ -57,6 +57,10 @@ class BrowserWindow : public TopLevelWindow,
   void OnRendererResponsive() override;
   void OnDraggableRegionsUpdated(
       const std::vector<mojom::DraggableRegionPtr>& regions) override;
+  void OnSetContentBounds(const gfx::Rect& rect) override;
+  void OnActivateContents() override;
+  void OnPageTitleUpdated(const base::string16& title,
+                          bool explicit_set) override;
 
   // NativeWindowObserver:
   void RequestPreferredWidth(int* width) override;

shell/browser/api/electron_api_top_level_window.cc

@@ -120,6 +120,9 @@ TopLevelWindow::~TopLevelWindow() {
   // Destroy the native window in next tick because the native code might be
   // iterating all windows.
   base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, window_.release());
+
+  // Remove global reference so the JS object can be garbage collected.
+  self_ref_.Reset();
 }
 
 void TopLevelWindow::InitWith(v8::Isolate* isolate,
@@ -135,6 +138,9 @@ void TopLevelWindow::InitWith(v8::Isolate* isolate,
     DCHECK(!parent.IsEmpty());
     parent->child_windows_.Set(isolate, weak_map_id(), wrapper);
   }
+
+  // Reference this object in case it got garbage collected.
+  self_ref_.Reset(isolate, wrapper);
 }
 
 void TopLevelWindow::WillCloseWindow(bool* prevent_default) {

shell/browser/api/electron_api_top_level_window.h

@@ -259,6 +259,9 @@ class TopLevelWindow : public gin_helper::TrackableObject<TopLevelWindow>,
 
   std::unique_ptr<NativeWindow> window_;
 
+  // Reference to JS wrapper to prevent garbage collection.
+  v8::Global<v8::Value> self_ref_;
+
   base::WeakPtrFactory<TopLevelWindow> weak_factory_;
 };
 

shell/browser/api/electron_api_web_contents.cc

@@ -705,8 +705,9 @@ void WebContents::BeforeUnloadFired(content::WebContents* tab,
 }
 
 void WebContents::SetContentsBounds(content::WebContents* source,
-                                    const gfx::Rect& pos) {
-  Emit("move", pos);
+                                    const gfx::Rect& rect) {
+  for (ExtendedWebContentsObserver& observer : observers_)
+    observer.OnSetContentBounds(rect);
 }
 
 void WebContents::CloseContents(content::WebContents* source) {
@@ -725,7 +726,8 @@ void WebContents::CloseContents(content::WebContents* source) {
 }
 
 void WebContents::ActivateContents(content::WebContents* source) {
-  Emit("activate");
+  for (ExtendedWebContentsObserver& observer : observers_)
+    observer.OnActivateContents();
 }
 
 void WebContents::UpdateTargetURL(content::WebContents* source,
@@ -1228,6 +1230,8 @@ void WebContents::TitleWasSet(content::NavigationEntry* entry) {
       final_title = title;
     }
   }
+  for (ExtendedWebContentsObserver& observer : observers_)
+    observer.OnPageTitleUpdated(final_title, explicit_set);
   Emit("page-title-updated", final_title, explicit_set);
 }
 

shell/browser/api/electron_api_web_contents.h

@@ -81,6 +81,10 @@ class ExtendedWebContentsObserver : public base::CheckedObserver {
   virtual void OnRendererResponsive() {}
   virtual void OnDraggableRegionsUpdated(
       const std::vector<mojom::DraggableRegionPtr>& regions) {}
+  virtual void OnSetContentBounds(const gfx::Rect& rect) {}
+  virtual void OnActivateContents() {}
+  virtual void OnPageTitleUpdated(const base::string16& title,
+                                  bool explicit_set) {}
 
  protected:
   ~ExtendedWebContentsObserver() override {}