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

content/browser/compositor/offscreen_browser_compositor_output_surface.h

 // Copyright 2015 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_OFFSCREEN_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 #define CONTENT_BROWSER_COMPOSITOR_OFFSCREEN_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_
 
 #include "base/cancelable_callback.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "content/browser/compositor/browser_compositor_output_surface.h"
 
 namespace ui {
 class CompositorVSyncManager;
 }
 
 namespace content {
 class CommandBufferProxyImpl;
+class GLHelper;
+class OwnedMailbox;
 
 class OffscreenBrowserCompositorOutputSurface
     : public BrowserCompositorOutputSurface {
  public:
   OffscreenBrowserCompositorOutputSurface(
       const scoped_refptr<ContextProviderCommandBuffer>& context,
       const scoped_refptr<ui::CompositorVSyncManager>& vsync_manager,
       scoped_ptr<BrowserCompositorOverlayCandidateValidator>
           overlay_candidate_validator);
 
   ~OffscreenBrowserCompositorOutputSurface() override;
 
  protected:
   // cc::OutputSurface:
   void EnsureBackbuffer() override;
   void DiscardBackbuffer() override;
   void Reshape(const gfx::Size& size, float scale_factor) override;
   void BindFramebuffer() override;
   void SwapBuffers(cc::CompositorFrame* frame) override;
 
+  // BrowserCompositorOutputSurface
+  scoped_refptr<OwnedMailbox> GetTextureMailbox() override;
+  base::Closure CreateCompositionStartedCallback() override;
 #if defined(OS_MACOSX)
   void OnSurfaceDisplayed() override {};
   void SetSurfaceSuspendedForRecycle(bool suspended) override {};
   bool SurfaceShouldNotShowFramesAfterSuspendForRecycle() const override;
 #endif
 
   uint32 fbo_;
   bool is_backbuffer_discarded_;
   uint32 backing_texture_id_;
+  bool needs_update_reflector_;
+
+  scoped_refptr<OwnedMailbox> mailbox_;
+  scoped_ptr<GLHelper> offline_compositor_gl_helper_;
 
   base::WeakPtrFactory<OffscreenBrowserCompositorOutputSurface>
       weak_ptr_factory_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(OffscreenBrowserCompositorOutputSurface);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_COMPOSITOR_OFFSCREEN_BROWSER_COMPOSITOR_OUTPUT_SURFACE_H_