Defer scroll offset change notification to browser

content/renderer/render_view_impl.h

Index: content/renderer/render_view_impl.h
diff --git a/content/renderer/render_view_impl.h b/content/renderer/render_view_impl.h
index e0932ea9ca55a3ef5986cbf7c910c10b22328203..a9d2204737e07da0e3ecec241afeba06cbc461c3 100644
--- a/content/renderer/render_view_impl.h
+++ b/content/renderer/render_view_impl.h
@@ -354,6 +354,7 @@ class CONTENT_EXPORT RenderViewImpl
   // blink::WebWidgetClient implementation ------------------------------------
 
   // Most methods are handled by RenderWidget.
+  virtual void didCommitAndDrawCompositorFrame();
   virtual void didFocus();
   virtual void didBlur();
   virtual void show(blink::WebNavigationPolicy policy);
@@ -651,9 +652,6 @@ class CONTENT_EXPORT RenderViewImpl
   // Sends a message and runs a nested message loop.
   bool SendAndRunNestedMessageLoop(IPC::SyncMessage* message);
 
-  // Called when the "pinned to left/right edge" state needs to be updated.
-  void UpdateScrollState(blink::WebFrame* frame);
-
   // IPC message handlers ------------------------------------------------------
   //
   // The documentation for these functions should be in
@@ -1017,6 +1015,8 @@ class CONTENT_EXPORT RenderViewImpl
   bool has_scrolled_focused_editable_node_into_rect_;
   gfx::Rect rect_for_scrolled_focused_editable_node_;
 
+  bool has_scrolled_main_frame_;
+
   // Helper objects ------------------------------------------------------------
 
   scoped_ptr<RenderFrameImpl> main_render_frame_;