Create RenderFrameProxyHost at time of swap-out instead of commit.

content/browser/frame_host/render_frame_host_manager.h

Index: content/browser/frame_host/render_frame_host_manager.h
diff --git a/content/browser/frame_host/render_frame_host_manager.h b/content/browser/frame_host/render_frame_host_manager.h
index f5ecf04df5064b57d705f6974475316523870ff9..9b48ef501ef81d015d2710db67d2fbcd2fb16822 100644
--- a/content/browser/frame_host/render_frame_host_manager.h
+++ b/content/browser/frame_host/render_frame_host_manager.h
@@ -58,12 +58,10 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
     // process is not shared, then the WebContentsImpl will act as though the
     // renderer is not running (i.e., it will render "sad tab"). This method is
     // automatically called from LoadURL.
-    //
-    // If you are attaching to an already-existing RenderView, you should call
-    // InitWithExistingID.
     virtual bool CreateRenderViewForRenderManager(
         RenderViewHost* render_view_host,
         int opener_route_id,
+        int proxy_routing_id,
         CrossProcessFrameConnector* cross_process_frame_connector) = 0;
     virtual void BeforeUnloadFiredFromRenderManager(
         bool proceed, const base::TimeTicks& proceed_time,
@@ -377,7 +375,9 @@ class CONTENT_EXPORT RenderFrameHostManager : public NotificationObserver {
   // initialized for another RenderFrameHost.
   // TODO(creis): opener_route_id is currently for the RenderViewHost but should
   // be for the RenderFrame, since frames can have openers.
-  bool InitRenderView(RenderViewHost* render_view_host, int opener_route_id);
+  bool InitRenderView(RenderViewHost* render_view_host,
+                      int opener_route_id,
+                      int proxy_routing_id);

[Charlie Reis, 2014/05/15 00:32:50]

It's a bit unclear what this is for.  Perhaps a comment would help.

[nasko, 2014/05/15 18:47:13]

Done.

 
   // Sets the pending RenderFrameHost/WebUI to be the active one. Note that this
   // doesn't require the pending render_frame_host_ pointer to be non-NULL,