Fix race conditions in window snapshot code.

content/browser/aura/software_browser_compositor_output_surface.cc

 // 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.
 
 #include "content/browser/aura/software_browser_compositor_output_surface.h"
 
+#include "base/message_loop/message_loop.h"
 #include "base/time/time.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/software_output_device.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "ui/events/latency_info.h"
 
 namespace content {
 
 SoftwareBrowserCompositorOutputSurface::SoftwareBrowserCompositorOutputSurface(
     scoped_ptr<cc::SoftwareOutputDevice> software_device)
     : cc::OutputSurface(software_device.Pass()) {}
 
 void SoftwareBrowserCompositorOutputSurface::SwapBuffers(
     cc::CompositorFrame* frame) {
   ui::LatencyInfo latency_info = frame->metadata.latency_info;
   latency_info.AddLatencyNumber(
       ui::INPUT_EVENT_LATENCY_TERMINATED_FRAME_SWAP_COMPONENT, 0, 0);
-  RenderWidgetHostImpl::CompositorFrameDrawn(latency_info);
+
+  base::MessageLoop::current()->PostTask(
+      FROM_HERE,
+      base::Bind(
+          &RenderWidgetHostImpl::CompositorFrameDrawn,
+          latency_info));
 }
 
 }  // namespace content