Ensure that before creating proxy of site A, RVH of site A is initialized.

content/browser/frame_host/render_frame_proxy_host.h

 // Copyright 2014 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_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_
 #define CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "content/browser/frame_host/render_frame_host_impl.h"
 #include "content/browser/site_instance_impl.h"
@@ skipping 88 matching lines @@
   bool OnMessageReceived(const IPC::Message& msg) override;
 
   CrossProcessFrameConnector* cross_process_frame_connector() {
     return cross_process_frame_connector_.get();
   }
 
   // Set the frame's opener to null in the renderer process in response to an
   // action in another renderer process.
   void DisownOpener();
 
+  void set_render_frame_proxy_created(bool created) {
+    render_frame_proxy_created_ = created;
+  }
+
+  // Returns if the renderer/ side counterpart for this proxy is alive.

[nasko, 2015/02/03 21:29:36]

nit: "if the RenderFrameProxy for this host"

[lazyboy, 2015/02/03 23:15:14]

Done.

+  bool is_render_frame_proxy_live() { return render_frame_proxy_created_; }
+
  private:
   // IPC Message handlers.
   void OnOpenURL(const FrameHostMsg_OpenURL_Params& params);
 
   // This RenderFrameProxyHost's routing id.
   int routing_id_;
 
   // The SiteInstance this proxy is associated with.
   scoped_refptr<SiteInstance> site_instance_;
 
   // The node in the frame tree where this proxy is located.
   FrameTreeNode* frame_tree_node_;
 
+  // True if we have a live RenderFrameProxy for this host.
+  bool render_frame_proxy_created_;
+
   // When a RenderFrameHost is in a different process from its parent in the
   // frame tree, this class connects its associated RenderWidgetHostView
   // to this RenderFrameProxyHost, which corresponds to the same frame in the
   // parent's renderer process.
   scoped_ptr<CrossProcessFrameConnector> cross_process_frame_connector_;
 
   // TODO(nasko): This can be removed once we don't have a swapped out state on
   // RenderFrameHosts. See https://crbug.com/357747.
   scoped_ptr<RenderFrameHostImpl> render_frame_host_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderFrameProxyHost);
 };
 
 }  // namespace
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_FRAME_PROXY_HOST_H_