Allow FlushSyncs to short circuit

content/common/gpu/gpu_channel.h

Index: content/common/gpu/gpu_channel.h
diff --git a/content/common/gpu/gpu_channel.h b/content/common/gpu/gpu_channel.h
index 242b7462c109a11f37cbb79524f2f513c0159257..602084ba370a89468430c1bccba5fcd9b54b2ef3 100644
--- a/content/common/gpu/gpu_channel.h
+++ b/content/common/gpu/gpu_channel.h
@@ -126,7 +126,7 @@ class GpuChannel : public IPC::Channel::Listener,
 
   bool OnControlMessageReceived(const IPC::Message& msg);
 
-  void HandleDeferredMessages();
+  void HandleMessage();
 
   // Message handlers.
   void OnInitialize(base::ProcessHandle renderer_process);
@@ -147,7 +147,7 @@ class GpuChannel : public IPC::Channel::Listener,
 
   scoped_ptr<IPC::SyncChannel> channel_;
 
-  std::queue<IPC::Message*> deferred_messages_;
+  std::deque<IPC::Message*> deferred_messages_;
 
   // The id of the renderer who is on the other side of the channel.
   int renderer_id_;
@@ -178,6 +178,7 @@ class GpuChannel : public IPC::Channel::Listener,
   gpu::gles2::DisallowedFeatures disallowed_features_;
   GpuWatchdog* watchdog_;
   bool software_;
+  bool handle_messages_scheduled_;
 
   ScopedRunnableMethodFactory<GpuChannel> task_factory_;