Fix race conditions in window snapshot code.

content/browser/aura/software_browser_compositor_output_surface.h

 // Copyright 2013 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_AURA_SOFTWARE_OUTPUT_SURFACE_H_
 #define CONTENT_BROWSER_AURA_SOFTWARE_OUTPUT_SURFACE_H_
 
 #include "cc/output/output_surface.h"
 
 namespace cc { class SoftwareOutputDevice; }
 
 namespace content {
 
 // TODO(danakj): Inherit from BrowserCompositorOutputSurface to share stuff like
 // reflectors, when we split the GL-specific stuff out of the class.
 class SoftwareBrowserCompositorOutputSurface : public cc::OutputSurface {
  public:
   static scoped_ptr<SoftwareBrowserCompositorOutputSurface> Create(
       scoped_ptr<cc::SoftwareOutputDevice> software_device) {
     return make_scoped_ptr(
         new SoftwareBrowserCompositorOutputSurface(software_device.Pass()));
   }
 
  private:
   explicit SoftwareBrowserCompositorOutputSurface(
       scoped_ptr<cc::SoftwareOutputDevice> software_device);
 
+  static void PostCompositorFrameDrawn(const ui::LatencyInfo& latency_info);
+
   virtual void SwapBuffers(cc::CompositorFrame* frame) OVERRIDE;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_AURA_SOFTWARE_OUTPUT_SURFACE_H_