[Extensions] Fix crash in extension uninstall dialog

chrome/browser/extensions/extension_uninstall_dialog.h

 // Copyright (c) 2012 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_EXTENSIONS_EXTENSION_UNINSTALL_DIALOG_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_UNINSTALL_DIALOG_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 73 matching lines @@
   // dialog.
   void HandleReportAbuse();
 
   // TODO(sashab): Remove protected members: crbug.com/397395
   Profile* const profile_;
 
   // The delegate we will call Accepted/Canceled on after confirmation dialog.
   Delegate* delegate_;
 
   // The extension we are showing the dialog for.
-  const Extension* extension_;
+  scoped_refptr<const Extension> extension_;
 
   // The extension triggering the dialog if the dialog was shown by
   // chrome.management.uninstall.
-  const Extension* triggering_extension_;
+  scoped_refptr<const Extension> triggering_extension_;
 
   // The extensions icon.
   gfx::ImageSkia icon_;
 
  private:
   // Sets the icon that will be used in the dialog. If |icon| contains an empty
   // image, then we use a default icon instead.
   void SetIcon(const gfx::Image& image);
 
   void OnImageLoaded(const std::string& extension_id, const gfx::Image& image);
 
   // Displays the prompt. This should only be called after loading the icon.
   // The implementations of this method are platform-specific.
   virtual void Show() = 0;
 
   base::MessageLoop* ui_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionUninstallDialog);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_UNINSTALL_DIALOG_H_