Draw the offscreen texture to reflector's surface without extra copy

content/browser/compositor/gpu_browser_compositor_output_surface.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #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 {
 class CompositorVSyncManager;
 }
 
 namespace content {
 class CommandBufferProxyImpl;
 class BrowserCompositorOverlayCandidateValidator;
+class ReflectorTexture;
 
 // Adapts a WebGraphicsContext3DCommandBufferImpl into a
 // cc::OutputSurface that also handles vsync parameter updates
 // arriving from the GPU process.
 class GpuBrowserCompositorOutputSurface
     : public BrowserCompositorOutputSurface {
  public:
   GpuBrowserCompositorOutputSurface(
       const scoped_refptr<ContextProviderCommandBuffer>& context,
       const scoped_refptr<ui::CompositorVSyncManager>& vsync_manager,
       scoped_ptr<BrowserCompositorOverlayCandidateValidator>
           overlay_candidate_validator);
 
   ~GpuBrowserCompositorOutputSurface() override;
 
  protected:
+  // BrowserCompositorOutputSurface:
+  void OnReflectorChanged() override;
+
   // cc::OutputSurface implementation.
   void SwapBuffers(cc::CompositorFrame* frame) override;
   bool BindToClient(cc::OutputSurfaceClient* client) override;
 
 #if defined(OS_MACOSX)
   void OnSurfaceDisplayed() override;
   void SetSurfaceSuspendedForRecycle(bool suspended) override;
   bool SurfaceShouldNotShowFramesAfterSuspendForRecycle() const override;
   enum ShouldShowFramesState {
     // Frames that come from the GPU process should appear on-screen.
@@ skipping 11 matching lines @@
 
   CommandBufferProxyImpl* GetCommandBufferProxy();
   void OnSwapBuffersCompleted(const std::vector<ui::LatencyInfo>& latency_info);
 
   base::CancelableCallback<void(const std::vector<ui::LatencyInfo>&)>
       swap_buffers_completion_callback_;
   base::CancelableCallback<void(base::TimeTicks timebase,
                                 base::TimeDelta interval)>
       update_vsync_parameters_callback_;
 
+  scoped_ptr<ReflectorTexture> reflector_texture_;
+
   DISALLOW_COPY_AND_ASSIGN(GpuBrowserCompositorOutputSurface);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_COMPOSITOR_GPU_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_