Cocoa: Implement media gallery dialog

chrome/browser/media_gallery/media_galleries_dialog_controller.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_MEDIA_GALLERY_MEDIA_GALLERIES_DIALOG_CONTROLLER_H_
 #define CHROME_BROWSER_MEDIA_GALLERY_MEDIA_GALLERIES_DIALOG_CONTROLLER_H_
 
 #include <list>
 #include <map>
 
+#include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string16.h"
 #include "chrome/browser/media_gallery/media_galleries_preferences.h"
 #include "ui/base/dialogs/select_file_dialog.h"
 #include "ui/gfx/native_widget_types.h"
 
 namespace extensions {
 class Extension;
 }
 
@@ skipping 83 matching lines @@
   // This is just a reference, but it's assumed that it won't become invalid
   // while the dialog is showing.
   const extensions::Extension& extension_;
 
   // This map excludes those galleries which have been blacklisted; it only
   // counts active known galleries.
   KnownGalleryPermissions known_galleries_;
   NewGalleryPermissions new_galleries_;
 
   // We run this callback when done.
-  const base::Callback<void(void)>& on_finish_;
+  const base::Callback<void(void)> on_finish_;
 
   // The model that tracks galleries and extensions' permissions.
   MediaGalleriesPreferences* preferences_;
 
   // The view that's showing.
   scoped_ptr<MediaGalleriesDialog> dialog_;
 
   scoped_refptr<ui::SelectFileDialog> select_folder_dialog_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaGalleriesDialogController);
 };
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_MEDIA_GALLERY_MEDIA_GALLERIES_DIALOG_CONTROLLER_H_