cc: Single-threaded impl-side painting for unit tests

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 b3a55b40d07568d0ca19aac90cdef0af65f0c185..42f2ff289a0ee0aa2228d8022b21a6ad29f71638 100644
--- a/cc/trees/single_thread_proxy.h
+++ b/cc/trees/single_thread_proxy.h
@@ -98,11 +98,11 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
       size_t limit_bytes,
       int priority_cutoff) OVERRIDE;
   virtual bool IsInsideDraw() OVERRIDE;
-  virtual void RenewTreePriority() OVERRIDE {}
+  virtual void RenewTreePriority() OVERRIDE;
   virtual void PostDelayedScrollbarFadeOnImplThread(
       const base::Closure& start_fade,
       base::TimeDelta delay) OVERRIDE {}
-  virtual void DidActivateSyncTree() OVERRIDE {}
+  virtual void DidActivateSyncTree() OVERRIDE;
   virtual void DidManageTiles() OVERRIDE;
   virtual void SetDebugState(const LayerTreeDebugState& debug_state) OVERRIDE {}
 
@@ -126,6 +126,7 @@ class CC_EXPORT SingleThreadProxy : public Proxy,
                          LayerTreeHostImpl::FrameData* frame);
   void DoSwap();
   void DidCommitAndDrawFrame();
+  void CommitComplete();
 
   bool ShouldComposite() const;
   void UpdateBackgroundAnimateTicking();