Fix scrollbar fade animation scheduling.

cc/trees/layer_tree_host_impl.h

Index: cc/trees/layer_tree_host_impl.h
diff --git a/cc/trees/layer_tree_host_impl.h b/cc/trees/layer_tree_host_impl.h
index e05e45bbfeac56854e6a2bf8cb0b8714b918c225..80e3bd37896b546f10a5e2f22defed64ebb01c95 100644
--- a/cc/trees/layer_tree_host_impl.h
+++ b/cc/trees/layer_tree_host_impl.h
@@ -131,7 +131,7 @@ class CC_EXPORT LayerTreeHostImpl
   virtual void DidChangeTopControlsPosition() OVERRIDE;
   virtual bool HaveRootScrollLayer() const OVERRIDE;
 
-  void StartScrollbarAnimation(base::TimeTicks now);
+  void StartScrollbarAnimation();
 
   struct CC_EXPORT FrameData : public RenderPassSink {
     FrameData();
@@ -370,6 +370,8 @@ class CC_EXPORT LayerTreeHostImpl
   base::TimeTicks CurrentFrameTimeTicks();
   base::Time CurrentFrameTime();
 
+  virtual base::TimeTicks CurrentPhysicalTimeTicks() const;
+
   scoped_ptr<base::Value> AsValue() const;
   scoped_ptr<base::Value> ActivationStateAsValue() const;
 
@@ -438,6 +440,8 @@ class CC_EXPORT LayerTreeHostImpl
 
   static LayerImpl* GetNonCompositedContentLayerRecursive(LayerImpl* layer);
 
+  void UpdateCurrentFrameTime(base::TimeTicks* ticks, base::Time* now) const;
+
   void StartScrollbarAnimationRecursive(LayerImpl* layer, base::TimeTicks time);
 
   scoped_ptr<OutputSurface> output_surface_;