Expose GpuMemoryBufferId through glGetImageivCHROMIUM.

gpu/command_buffer/service/in_process_command_buffer.h

Index: gpu/command_buffer/service/in_process_command_buffer.h
diff --git a/gpu/command_buffer/service/in_process_command_buffer.h b/gpu/command_buffer/service/in_process_command_buffer.h
index c20570a4833d2b8f9feca5bc3f22827e37b24906..f8d1c9cf387be75545291b734138e026cc6ac2d7 100644
--- a/gpu/command_buffer/service/in_process_command_buffer.h
+++ b/gpu/command_buffer/service/in_process_command_buffer.h
@@ -117,6 +117,7 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer,
                                      size_t height,
                                      unsigned internalformat,
                                      unsigned usage) override;
+  int32_t GetImageGpuMemoryBufferId(unsigned image_id) override;
   void SignalQuery(uint32_t query_id, const base::Closure& callback) override;
   void SetLock(base::Lock*) override;
   void EnsureWorkVisible() override;
@@ -277,6 +278,9 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer,
   // the client thread.
   std::unique_ptr<base::SequenceChecker> sequence_checker_;
 
+  // A map from image id to GpuMemoryBuffer id.
+  std::map<int32_t, int32_t> image_gmb_ids_map_;
+
   base::WeakPtr<InProcessCommandBuffer> client_thread_weak_ptr_;
   base::WeakPtr<InProcessCommandBuffer> gpu_thread_weak_ptr_;
   base::WeakPtrFactory<InProcessCommandBuffer> client_thread_weak_ptr_factory_;
@@ -312,6 +316,7 @@ class GPU_EXPORT GpuInProcessThread
   scoped_refptr<gpu::gles2::ShaderTranslatorCache> shader_translator_cache_;
   scoped_refptr<gpu::gles2::FramebufferCompletenessCache>
       framebuffer_completeness_cache_;
+
   DISALLOW_COPY_AND_ASSIGN(GpuInProcessThread);
 };