cc: Delay start of scrollbar animation setNeedsRedraw.

cc/thread_proxy.h

Index: cc/thread_proxy.h
diff --git a/cc/thread_proxy.h b/cc/thread_proxy.h
index e508b76461f5f8d9c6242c694d3067b1f1ea8c4c..91ea1fc4e862f38d5941aa2fdf41c0ec17d91a22 100644
--- a/cc/thread_proxy.h
+++ b/cc/thread_proxy.h
@@ -86,6 +86,8 @@ class ThreadProxy : public Proxy,
   virtual void SendManagedMemoryStats() OVERRIDE;
   virtual bool IsInsideDraw() OVERRIDE;
   virtual void RenewTreePriority() OVERRIDE;
+  virtual void RequestScrollbarAnimationOnImplThread(base::TimeDelta delay)
+      OVERRIDE;
 
   // SchedulerClient implementation
   virtual void scheduledActionBeginFrame() OVERRIDE;
@@ -186,6 +188,7 @@ class ThreadProxy : public Proxy,
                            base::DictionaryValue* state) const;
   void RenewTreePriorityOnImplThread();
   void DidSwapUseIncompleteTileOnImplThread();
+  void StartScrollbarAnimationOnImplThread();
 
   // Accessed on main thread only.