Switch the page-capturing machinery to use the new hooks.

content/renderer/render_frame_impl.h

Index: content/renderer/render_frame_impl.h
diff --git a/content/renderer/render_frame_impl.h b/content/renderer/render_frame_impl.h
index 68c42c4b99b349da16eb6ee366c99eb7d6b87b43..918c6559f3983b4a265d2183da9818f477332159 100644
--- a/content/renderer/render_frame_impl.h
+++ b/content/renderer/render_frame_impl.h
@@ -203,6 +203,10 @@ class CONTENT_EXPORT RenderFrameImpl
     render_frame_proxy_ = proxy;
   }
 
+  // Called by RenderWidget when meaningful layout has happened.
+  // See RenderFrameObserver::DidMeaningfulLayout declaration for details.
+  void DidMeaningfulLayout(blink::WebMeaningfulLayout layout_type);
+
   // Out-of-process child frames receive a signal from RenderWidgetCompositor
   // when a compositor frame has committed.
   void DidCommitCompositorFrame();