Make a clean interface for dialog callbacks.

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 111 matching lines @@
   // NotificationObserver
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
   // Overridden from JavaScriptDialogDelegate:
   virtual void OnDialogClosed(IPC::Message* reply_msg,
                               bool success,
                               const string16& user_input) OVERRIDE;
   virtual gfx::NativeWindow GetDialogRootWindow() OVERRIDE;
-  virtual TabContents* AsTabContents() OVERRIDE;
-  virtual ExtensionHost* AsExtensionHost() OVERRIDE;
 
   virtual void UpdateInspectorSetting(const std::string& key,
                                       const std::string& value);
   virtual void ClearInspectorSettings();
 
   // Helper to find the BackgroundContents that originated the given request.
   // Can be NULL if the page has been closed or some other error occurs.
   // Should only be called from the UI thread, since it accesses
   // BackgroundContents.
   static BackgroundContents* GetBackgroundContentsByID(int render_process_id,
@@ skipping 27 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_