Refactoring the way begin frame sources inside scheduler work.

cc/trees/single_thread_proxy.h

Index: cc/trees/single_thread_proxy.h
diff --git a/cc/trees/single_thread_proxy.h b/cc/trees/single_thread_proxy.h
index 5de42b5d44be3065b1cde5a490c5eaf821e68334..97ba5e37a977b7f1824669c2aba1fd7249537d0d 100644
--- a/cc/trees/single_thread_proxy.h
+++ b/cc/trees/single_thread_proxy.h
@@ -53,13 +53,11 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
   // LayerTreeHostImplClient implementation
   virtual void UpdateRendererCapabilitiesOnImplThread() OVERRIDE;
   virtual void DidLoseOutputSurfaceOnImplThread() OVERRIDE;
-  virtual void CommitVSyncParameters(base::TimeTicks timebase,
-                                     base::TimeDelta interval) OVERRIDE {}
   virtual void SetEstimatedParentDrawTime(base::TimeDelta draw_time) OVERRIDE {}
   virtual void SetMaxSwapsPendingOnImplThread(int max) OVERRIDE {}
   virtual void DidSwapBuffersOnImplThread() OVERRIDE;
   virtual void DidSwapBuffersCompleteOnImplThread() OVERRIDE;
-  virtual void BeginFrame(const BeginFrameArgs& args) OVERRIDE {}
+  // TODO(mithro): Why is this an empty???
   virtual void OnCanDrawStateChanged(bool can_draw) OVERRIDE;
   virtual void NotifyReadyToActivate() OVERRIDE;
   virtual void SetNeedsRedrawOnImplThread() OVERRIDE;
@@ -101,7 +99,6 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
   void DidSwapFrame();
 
   bool ShouldComposite() const;
-  void UpdateBackgroundAnimateTicking();
 
   // Accessed on main thread only.
   LayerTreeHost* layer_tree_host_;