Implement proper synchronization between HW video decode IPC and CommandBuffer.

webkit/plugins/ppapi/mock_plugin_delegate.h

Index: webkit/plugins/ppapi/mock_plugin_delegate.h
diff --git a/webkit/plugins/ppapi/mock_plugin_delegate.h b/webkit/plugins/ppapi/mock_plugin_delegate.h
index 0b913486a06bddeca647f6546e9e077b70cd6543..cdcd40f3ee42ec9e29808c49f72818da03497fa6 100644
--- a/webkit/plugins/ppapi/mock_plugin_delegate.h
+++ b/webkit/plugins/ppapi/mock_plugin_delegate.h
@@ -24,7 +24,8 @@ class MockPluginDelegate : public PluginDelegate {
   virtual PlatformContext3D* CreateContext3D();
   virtual PlatformVideoDecoder* CreateVideoDecoder(
       media::VideoDecodeAccelerator::Client* client,
-      int command_buffer_route_id);
+      int32 command_buffer_route_id,
+      CommandBufferHelper* cmd_buffer_helper);
   virtual PlatformAudio* CreateAudio(uint32_t sample_rate,
                                      uint32_t sample_count,
                                      PlatformAudio::Client* client);