Make RenderFrame{Host} objects routable.

content/public/browser/render_frame_host.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_BROWSER_RENDER_FRAME_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_FRAME_HOST_H_
 
 #include "content/common/content_export.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_sender.h"
 
 namespace content {
 
 // The interface provides a communication conduit with a frame in the renderer.
 class CONTENT_EXPORT RenderFrameHost : public IPC::Listener,
                                        public IPC::Sender {
+ public:
+  virtual ~RenderFrameHost() {}
+
  private:
   // This interface should only be implemented inside content.
   friend class RenderFrameHostImpl;
   RenderFrameHost() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_FRAME_HOST_H_