Added command buffer implementation of WebGL which runs in the sandbox....

chrome/browser/gpu_process_host.h

Index: chrome/browser/gpu_process_host.h
===================================================================
--- chrome/browser/gpu_process_host.h	(revision 42776)
+++ chrome/browser/gpu_process_host.h	(working copy)
@@ -53,6 +53,10 @@
   // on completion.
   void EstablishGpuChannel(int renderer_id);
 
+  // Sends a reply message later when the next GpuHostMsg_SynchronizeReply comes
+  // in.
+  void Synchronize(int renderer_id, IPC::Message* reply);
+
  private:
   friend struct DefaultSingletonTraits<GpuProcessHost>;
 
@@ -74,6 +78,7 @@
 
   // Message handlers.
   void OnChannelEstablished(const IPC::ChannelHandle& channel_handle);
+  void OnSynchronizeReply(int renderer_id);
 
   void ReplyToRenderer(int renderer_id,
                        const IPC::ChannelHandle& channel);
@@ -104,6 +109,9 @@
   // because the queued messages may have dependencies on the init messages.
   std::queue<IPC::Message*> queued_messages_;
 
+  // The pending synchronization requests we need to reply to.
+  std::queue<IPC::Message*> queued_synchronization_replies_;
+
   DISALLOW_COPY_AND_ASSIGN(GpuProcessHost);
 };