Avoid creating a RenderWidgetHostView for proxies.

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index 9f9ae02bbc4b3883fff4b4c120160899d999614a..9ad0214846b0c90c3607e752e1727f9a3a0c9ac6 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -80,11 +80,8 @@ struct ResourceResponse;
 enum CreateRenderFrameFlags {
   // The RFH will be initially placed on the swapped out hosts list.
   CREATE_RF_SWAPPED_OUT = 1 << 0,
-  // The new RenderFrame is being created for a navigation of the
-  // top-level frame.
-  CREATE_RF_FOR_MAIN_FRAME_NAVIGATION = 1 << 1,
   // The RenderFrame is initially hidden.
-  CREATE_RF_HIDDEN = 1 << 2,
+  CREATE_RF_HIDDEN = 1 << 1,
 };
 
 class CONTENT_EXPORT RenderFrameHostImpl