Always use the WebFrameWidget when attaching the root graphics

third_party/WebKit/Source/web/WebFrameWidgetImpl.h

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 115 matching lines @@
     CompositorProxyClient* createCompositorProxyClient() override;
 
     WebWidgetClient* client() const override { return m_client; }
 
     Frame* focusedCoreFrame() const;
 
     // Returns the currently focused Element or null if no element has focus.
     Element* focusedElement() const;
 
     PaintLayerCompositor* compositor() const;
-    void setRootGraphicsLayer(GraphicsLayer*);
-    void attachCompositorAnimationTimeline(CompositorAnimationTimeline*);
-    void detachCompositorAnimationTimeline(CompositorAnimationTimeline*);
+    void setRootGraphicsLayer(GraphicsLayer*) override;
+    void attachCompositorAnimationTimeline(CompositorAnimationTimeline*) override;
+    void detachCompositorAnimationTimeline(CompositorAnimationTimeline*) override;
 
     // Exposed for the purpose of overriding device metrics.
     void sendResizeEventAndRepaint();
 
     void updateMainFrameLayoutSize();
 
     void setIgnoreInputEvents(bool newValue);
 
     // Returns the page object associated with this widget. This may be null when
     // the page is shutting down, but will be valid at all other times.
@@ skipping 81 matching lines @@
     WebColor m_baseBackgroundColor;
 
     SelfKeepAlive<WebFrameWidgetImpl> m_selfKeepAlive;
 };
 
 DEFINE_TYPE_CASTS(WebFrameWidgetImpl, WebFrameWidget, widget, widget->forSubframe(), widget.forSubframe());
 
 } // namespace blink
 
 #endif