Remove GpuHostMsg_FrameDrawn and replace with client channel swap ack

content/browser/compositor/gpu_browser_compositor_output_surface.h

Index: content/browser/compositor/gpu_browser_compositor_output_surface.h
diff --git a/content/browser/compositor/gpu_browser_compositor_output_surface.h b/content/browser/compositor/gpu_browser_compositor_output_surface.h
index 5f47a30d230bd5d39589fa88f18d9c54ba7fe760..3116d355a364eaa1a726a29c50d39d8dd58cff06 100644
--- a/content/browser/compositor/gpu_browser_compositor_output_surface.h
+++ b/content/browser/compositor/gpu_browser_compositor_output_surface.h
@@ -5,6 +5,7 @@
 #ifndef CONTENT_BROWSER_COMPOSITOR_GPU_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 #define CONTENT_BROWSER_COMPOSITOR_GPU_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 
+#include "base/cancelable_callback.h"
 #include "content/browser/compositor/browser_compositor_output_surface.h"
 
 namespace ui {
@@ -16,6 +17,7 @@ class OverlayCandidateValidator;
 }
 
 namespace content {
+class CommandBufferProxyImpl;
 
 // Adapts a WebGraphicsContext3DCommandBufferImpl into a
 // cc::OutputSurface that also handles vsync parameter updates
@@ -35,6 +37,13 @@ class GpuBrowserCompositorOutputSurface
  protected:
   // cc::OutputSurface implementation.
   virtual void SwapBuffers(cc::CompositorFrame* frame) override;
+  virtual bool BindToClient(cc::OutputSurfaceClient* client) override;
+
+  CommandBufferProxyImpl* GetCommandBufferProxy();
+  void OnSwapBuffersCompleted(const std::vector<ui::LatencyInfo>& latency_info);
+
+  base::CancelableCallback<void(const std::vector<ui::LatencyInfo>&)>
+      swap_buffers_completion_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuBrowserCompositorOutputSurface);
 };