WIP: Plumbing input event latency reporting through Mus GPU.

gpu/ipc/in_process_command_buffer.h

Index: gpu/ipc/in_process_command_buffer.h
diff --git a/gpu/ipc/in_process_command_buffer.h b/gpu/ipc/in_process_command_buffer.h
index 1d4162e462bb91d52df96fb13d88bcd1a7f58a20..b5eed7b4e8014ccca61ce174d01817b5ea88210e 100644
--- a/gpu/ipc/in_process_command_buffer.h
+++ b/gpu/ipc/in_process_command_buffer.h
@@ -81,6 +81,9 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer,
                                           public ImageTransportSurfaceDelegate {
  public:
   class Service;
+  typedef base::Callback<void(const std::vector<ui::LatencyInfo>&)>
+      LatencyInfoCallback;
+
   explicit InProcessCommandBuffer(const scoped_refptr<Service>& service);
   ~InProcessCommandBuffer() override;
 
@@ -96,6 +99,8 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer,
                   ImageFactory* image_factory,
                   scoped_refptr<base::SingleThreadTaskRunner> task_runner);
 
+  void SetLatencyInfo(const std::vector<ui::LatencyInfo>& latency_info);
+
   // CommandBuffer implementation:
   State GetLastState() override;
   void Flush(int32_t put_offset) override;
@@ -285,6 +290,9 @@ class GPU_EXPORT InProcessCommandBuffer : public CommandBuffer,
   bool delayed_work_pending_;
   ImageFactory* image_factory_;
 
+  LatencyInfoCallback latency_info_callback_;
+  std::vector<ui::LatencyInfo> latency_info_;
+
   // Members accessed on the client thread:
   GpuControlClient* gpu_control_client_;
 #if DCHECK_IS_ON()