cc: Add message passing mechanism to micro benchmarking.

cc/debug/micro_benchmark.h

Index: cc/debug/micro_benchmark.h
diff --git a/cc/debug/micro_benchmark.h b/cc/debug/micro_benchmark.h
index f179fb9544d200ef30373fc4be88b1836c9469ea..1654c368f1dc3be7cf6b48d7b908959f82524f94 100644
--- a/cc/debug/micro_benchmark.h
+++ b/cc/debug/micro_benchmark.h
@@ -29,10 +29,14 @@ class CC_EXPORT MicroBenchmark {
 
   bool IsDone() const;
   virtual void DidUpdateLayers(LayerTreeHost* host);
+  int id() const { return id_; }
+  void set_id(int id) { id_ = id; }
 
   virtual void RunOnLayer(Layer* layer);
   virtual void RunOnLayer(PictureLayer* layer);
 
+  virtual bool ProcessMessage(scoped_ptr<base::Value> value);
+
   bool ProcessedForBenchmarkImpl() const;
   scoped_ptr<MicroBenchmarkImpl> GetBenchmarkImpl(
       scoped_refptr<base::MessageLoopProxy> origin_loop);
@@ -47,6 +51,7 @@ class CC_EXPORT MicroBenchmark {
   DoneCallback callback_;
   bool is_done_;
   bool processed_for_benchmark_impl_;
+  int id_;
 };
 
 }  // namespace cc