Fix for cant reopen file dialog after close it by x button or alt+f4

chrome/browser/ui/views/extensions/extension_dialog.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_UI_VIEWS_EXTENSIONS_EXTENSION_DIALOG_H_
 #define CHROME_BROWSER_UI_VIEWS_EXTENSIONS_EXTENSION_DIALOG_H_
 #pragma once
 
 #include "base/memory/ref_counted.h"
 #include "content/public/browser/notification_observer.h"
@@ skipping 41 matching lines @@
   // Sets the window title.
   void set_title(const string16& title) { window_title_ = title; }
 
   ExtensionHost* host() const { return extension_host_.get(); }
 
   // views::WidgetDelegate overrides.
   virtual bool CanResize() const OVERRIDE;
   virtual bool IsModal() const OVERRIDE;
   virtual bool ShouldShowWindowTitle() const OVERRIDE;
   virtual string16 GetWindowTitle() const OVERRIDE;
+  virtual void WindowClosing() OVERRIDE;
   virtual void DeleteDelegate() OVERRIDE;
   virtual views::Widget* GetWidget() OVERRIDE;
   virtual const views::Widget* GetWidget() const OVERRIDE;
   virtual views::View* GetContentsView() OVERRIDE;
 
   // content::NotificationObserver overrides.
   virtual void Observe(int type,
                        const content::NotificationSource& source,
                        const content::NotificationDetails& details) OVERRIDE;
 
@@ skipping 17 matching lines @@
 
   content::NotificationRegistrar registrar_;
 
   // The observer of this popup.
   ExtensionDialogObserver* observer_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionDialog);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_EXTENSIONS_EXTENSION_DIALOG_H_