Prevent the browser process from creating duplicate RenderViewHosts.

content/browser/web_contents/web_contents_impl.h

 // Copyright (c) 2012 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_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 388 matching lines @@
       RenderViewHost* render_view_host,
       const FileChooserParams& params) OVERRIDE;
   virtual void ToggleFullscreenMode(bool enter_fullscreen) OVERRIDE;
   virtual bool IsFullscreenForCurrentTab() const OVERRIDE;
   virtual void UpdatePreferredSize(const gfx::Size& pref_size) OVERRIDE;
   virtual void ResizeDueToAutoResize(const gfx::Size& new_size) OVERRIDE;
   virtual void RequestToLockMouse(bool user_gesture,
                                   bool last_unlocked_by_target) OVERRIDE;
   virtual void LostMouseLock() OVERRIDE;
   virtual void CreateNewWindow(
+      int render_process_id,
       int route_id,
       int main_frame_route_id,
       const ViewHostMsg_CreateWindow_Params& params,
       SessionStorageNamespace* session_storage_namespace) OVERRIDE;
   virtual void CreateNewWidget(int route_id,
                                blink::WebPopupType popup_type) OVERRIDE;
   virtual void CreateNewFullscreenWidget(int route_id) OVERRIDE;
   virtual void ShowCreatedWindow(int route_id,
                                  WindowOpenDisposition disposition,
                                  const gfx::Rect& initial_pos,
@@ skipping 569 matching lines @@
   // Maps the ids of pending image downloads to their callbacks
   typedef std::map<int, ImageDownloadCallback> ImageDownloadMap;
   ImageDownloadMap image_download_map_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_IMPL_H_