Add the main frame routing ID to WebContentsDelegate, use it in BackgroundContents.

extensions/browser/guest_view/extension_options/extension_options_guest.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 EXTENSIONS_BROWSER_GUEST_VIEW_EXTENSION_OPTIONS_EXTENSION_OPTIONS_GUEST_H_
 #define EXTENSIONS_BROWSER_GUEST_VIEW_EXTENSION_OPTIONS_EXTENSION_OPTIONS_GUEST_H_
 
 #include "base/macros.h"
 #include "extensions/browser/extension_function_dispatcher.h"
 #include "extensions/browser/guest_view/extension_options/extension_options_guest_delegate.h"
@@ skipping 33 matching lines @@
 
   // content::WebContentsDelegate implementation.
   content::WebContents* OpenURLFromTab(
       content::WebContents* source,
       const content::OpenURLParams& params) override;
   void CloseContents(content::WebContents* source) override;
   bool HandleContextMenu(const content::ContextMenuParams& params) override;
   bool ShouldCreateWebContents(
       content::WebContents* web_contents,
       int route_id,
+      int main_frame_route_id,
       WindowContainerType window_container_type,
       const base::string16& frame_name,
       const GURL& target_url,
       const std::string& partition_id,
       content::SessionStorageNamespace* session_storage_namespace) override;
 
   // content::WebContentsObserver implementation.
   void DidNavigateMainFrame(
       const content::LoadCommittedDetails& details,
       const content::FrameNavigateParams& params) override;
@@ skipping 13 matching lines @@
       extension_options_guest_delegate_;
   GURL options_page_;
   bool has_navigated_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionOptionsGuest);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_GUEST_VIEW_EXTENSION_OPTIONS_EXTENSION_OPTIONS_GUEST_H_