cc: Add testing stubs for proxy test

cc/trees/layer_tree_host.h

Index: cc/trees/layer_tree_host.h
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index 508a7281ee9a7acdd2b5c3c2f1dc3f97a36c0fbf..22b674b14defc168dc5b83bc1d8c2514b58a3a2d 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -309,7 +309,8 @@ class CC_EXPORT LayerTreeHost {
   LayerTreeHost(LayerTreeHostClient* client,
                 SharedBitmapManager* manager,
                 const LayerTreeSettings& settings);
-  void InitializeThreaded(
+  // virtual for test.

[danakj, 2014/04/24 16:03:15]

drop the comment.

[simonhong, 2014/04/25 00:42:35]

Done.

+  virtual void InitializeThreaded(
       scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner);
   void InitializeSingleThreaded(
       LayerTreeHostSingleThreadClient* single_thread_client);
@@ -317,12 +318,11 @@ class CC_EXPORT LayerTreeHost {
   void SetOutputSurfaceLostForTesting(bool is_lost) {
     output_surface_lost_ = is_lost;
   }
+  void InitializeProxy(scoped_ptr<Proxy> proxy);
 
   MicroBenchmarkController micro_benchmark_controller_;
 
  private:
-  void InitializeProxy(scoped_ptr<Proxy> proxy);
-
   void PaintLayerContents(
       const RenderSurfaceLayerList& render_surface_layer_list,
       ResourceUpdateQueue* queue,