OOPIF: report both original and destination rfh in AboutToNavigateRenderFrame.

content/browser/frame_host/navigator_delegate.h

Index: content/browser/frame_host/navigator_delegate.h
diff --git a/content/browser/frame_host/navigator_delegate.h b/content/browser/frame_host/navigator_delegate.h
index 1de561ba54f959f23e202e4ec0586092dd90200c..94b7b39fe9355a888fed204fdf06a0ae3a223548 100644
--- a/content/browser/frame_host/navigator_delegate.h
+++ b/content/browser/frame_host/navigator_delegate.h
@@ -82,7 +82,8 @@ class CONTENT_EXPORT NavigatorDelegate {
 
   // Notifies the Navigator embedder that it is beginning to navigate a frame.
   virtual void AboutToNavigateRenderFrame(
-      RenderFrameHostImpl* render_frame_host) {}
+      RenderFrameHostImpl* old_host,
+      RenderFrameHostImpl* new_host) {}
 
   // Notifies the Navigator embedder that a navigation to pending
   // NavigationEntry has started in the browser process.