gpu: Add GpuFence framework.

gpu/ipc/service/gpu_command_buffer_stub.h

Index: gpu/ipc/service/gpu_command_buffer_stub.h
diff --git a/gpu/ipc/service/gpu_command_buffer_stub.h b/gpu/ipc/service/gpu_command_buffer_stub.h
index a0999f8c059b9775ec9edf5622e6ff88748e006a..b0d678a8e24939bb277069c08761b64e1ef0980f 100644
--- a/gpu/ipc/service/gpu_command_buffer_stub.h
+++ b/gpu/ipc/service/gpu_command_buffer_stub.h
@@ -49,6 +49,7 @@ class MailboxManager;
 
 struct GPUCreateCommandBufferConfig;
 struct GpuCommandBufferMsg_CreateImage_Params;
+struct GpuCommandBufferMsg_CreateFence_Params;
 struct GpuCommandBufferMsg_SwapBuffersCompleted_Params;
 
 namespace gpu {
@@ -194,6 +195,8 @@ class GPU_EXPORT GpuCommandBufferStub
   void OnCreateStreamTexture(uint32_t texture_id,
                              int32_t stream_id,
                              bool* succeeded);
+  void OnCreateFence(const GpuCommandBufferMsg_CreateFence_Params& params);
+  void OnDestroyFence(int32_t id);
   void OnCommandProcessed();
   void OnParseError();