cc: Add message passing mechanism to micro benchmarking.

cc/trees/layer_tree_host.cc

Index: cc/trees/layer_tree_host.cc
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 82a49b5c35a5cf8638ac6eb380b7834cafc31910..5c78759f31f50ec8ba296198c6a0df1498e874ea 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -1217,7 +1217,7 @@ void LayerTreeHost::RegisterViewportLayers(
   outer_viewport_scroll_layer_ = outer_viewport_scroll_layer;
 }
 
-bool LayerTreeHost::ScheduleMicroBenchmark(
+int LayerTreeHost::ScheduleMicroBenchmark(
     const std::string& benchmark_name,
     scoped_ptr<base::Value> value,
     const MicroBenchmark::DoneCallback& callback) {
@@ -1225,6 +1225,11 @@ bool LayerTreeHost::ScheduleMicroBenchmark(
       benchmark_name, value.Pass(), callback);
 }
 
+bool LayerTreeHost::SendMessageToMicroBenchmark(int id,
+                                                scoped_ptr<base::Value> value) {
+  return micro_benchmark_controller_.SendMessage(id, value.Pass());
+}
+
 void LayerTreeHost::InsertSwapPromiseMonitor(SwapPromiseMonitor* monitor) {
   swap_promise_monitor_.insert(monitor);
 }