Allow CopyFromBackingStore to fallback to copying from the renderer side if the accelerated surface…

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index 680c85ad510bd435edb2bac15f0001c940ce7fba..5444af16ebb4ff8bdf28722781fe3749ebd6afa5 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -317,6 +317,7 @@ class CONTENT_EXPORT RenderWidget
   void OnImeBatchStateChanged(bool is_begin);
   void OnShowImeIfNeeded();
 #endif
+  void OnSnapshot(const gfx::Rect& src_subrect);
 
   // Notify the compositor about a change in viewport size. This should be
   // used only with auto resize mode WebWidgets, as normal WebWidgets should
@@ -478,6 +479,8 @@ class CONTENT_EXPORT RenderWidget
   WebKit::WebGraphicsContext3D* CreateGraphicsContext3D(
       const WebKit::WebGraphicsContext3D::Attributes& attributes);
 
+  bool OnSnapshotHelper(const gfx::Rect& src_subrect, SkBitmap* bitmap);
+
   // Routing ID that allows us to communicate to the parent browser process
   // RenderWidgetHost. When MSG_ROUTING_NONE, no messages may be sent.
   int32 routing_id_;