Fix race conditions in window snapshot code.

content/browser/aura/software_browser_compositor_output_surface.cc

Index: content/browser/aura/software_browser_compositor_output_surface.cc
diff --git a/content/browser/aura/software_browser_compositor_output_surface.cc b/content/browser/aura/software_browser_compositor_output_surface.cc
index f196c634c40fbc700dcde12aff6c5a24585fac1c..773e7df75bb6edc62e1ded4cf8fe07e71472e616 100644
--- a/content/browser/aura/software_browser_compositor_output_surface.cc
+++ b/content/browser/aura/software_browser_compositor_output_surface.cc
@@ -4,6 +4,7 @@
 
 #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"
@@ -21,7 +22,12 @@ void SoftwareBrowserCompositorOutputSurface::SwapBuffers(
   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