Get rid of extensions dependency from content\browser.

chrome/browser/tab_contents/background_contents.h

 // Copyright (c) 2011 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 CHROME_BROWSER_TAB_CONTENTS_BACKGROUND_CONTENTS_H_
 #define CHROME_BROWSER_TAB_CONTENTS_BACKGROUND_CONTENTS_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 135 matching lines @@
   // Should only be called from the UI thread, since it accesses
   // BackgroundContents.
   static BackgroundContents* GetBackgroundContentsByID(int render_process_id,
                                                        int render_view_id);
 
  protected:
   // Exposed for testing.
   BackgroundContents();
 
  private:
+  // Message handlers.
+  void OnPostMessage(int port_id, const std::string& message);
+
   // The delegate for this BackgroundContents.
   Delegate* delegate_;
 
   // The host for our HTML content.
   RenderViewHost* render_view_host_;
 
   // Common implementations of some RenderViewHostDelegate::View methods.
   RenderViewHostDelegateViewHelper delegate_view_helper_;
 
   // The URL being hosted.
@@ skipping 13 matching lines @@
   BackgroundContents* contents;
 
   // The name of the parent frame for these contents.
   const string16& frame_name;
 
   // The ID of the parent application (if any).
   const string16& application_id;
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_BACKGROUND_CONTENTS_H_