Refactor AppModalDialogQueue and move JS Alert boxes into a MVC.

chrome/views/window/app_modal_dialog_delegate.h

-// Copyright (c) 2006-2008 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_VIEWS_WINDOW_APP_MODAL_DIALOG_DELEGATE_H_
-#define CHROME_VIEWS_WINDOW_APP_MODAL_DIALOG_DELEGATE_H_
-
-#include "chrome/views/window/dialog_delegate.h"
-
-namespace views {
-
-// Pure virtual interface for a window which is app modal.
-class AppModalDialogDelegate : public DialogDelegate {
- public:
-  // Called by the app modal window queue when it is time to show this window.
-  virtual void ShowModalDialog() = 0;
-
-  // Called by the app modal window queue to activate the window.
-  virtual void ActivateModalDialog() = 0;
-};
-
-} // namespace views
-
-#endif  // #ifndef CHROME_VIEWS_WINDOW_APP_MODAL_DIALOG_DELEGATE_H_