cc: Add message passing mechanism to micro benchmarking.

cc/trees/layer_tree_host.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_TREES_LAYER_TREE_HOST_H_
 #define CC_TREES_LAYER_TREE_HOST_H_
 
 #include <limits>
 #include <list>
 #include <set>
@@ skipping 257 matching lines @@
   virtual void DeleteUIResource(UIResourceId id);
   // Put the recreation of all UI resources into the resource queue after they
   // were evicted on the impl thread.
   void RecreateUIResources();
 
   virtual gfx::Size GetUIResourceSize(UIResourceId id) const;
 
   bool UsingSharedMemoryResources();
   int id() const { return id_; }
 
-  bool ScheduleMicroBenchmark(const std::string& benchmark_name,
-                              scoped_ptr<base::Value> value,
-                              const MicroBenchmark::DoneCallback& callback);
+  // Returns the id of the benchmark on success, 0 otherwise.
+  int ScheduleMicroBenchmark(const std::string& benchmark_name,
+                             scoped_ptr<base::Value> value,
+                             const MicroBenchmark::DoneCallback& callback);
+  // Returns true if the message was successfully delivered and handled.
+  bool SendMessageToMicroBenchmark(int id, scoped_ptr<base::Value> value);
 
   // When a SwapPromiseMonitor is created on the main thread, it calls
   // InsertSwapPromiseMonitor() to register itself with LayerTreeHost.
   // When the monitor is destroyed, it calls RemoveSwapPromiseMonitor()
   // to unregister itself.
   void InsertSwapPromiseMonitor(SwapPromiseMonitor* monitor);
   void RemoveSwapPromiseMonitor(SwapPromiseMonitor* monitor);
 
   // Call this function when you expect there to be a swap buffer.
   // See swap_promise.h for how to use SwapPromise.
@@ skipping 149 matching lines @@
 
   ScopedPtrVector<SwapPromise> swap_promise_list_;
   std::set<SwapPromiseMonitor*> swap_promise_monitor_;
 
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
 }  // namespace cc
 
 #endif  // CC_TREES_LAYER_TREE_HOST_H_