Notificaitons refactor step 2

ui/message_center/notification_view.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 UI_MESSAGE_CENTER_NOTIFICATION_VIEW_H_
 #define UI_MESSAGE_CENTER_NOTIFICATION_VIEW_H_
 
 #include "ui/message_center/message_view.h"
 #include "ui/message_center/notification_list.h"
 
 namespace message_center {
 
 // View that displays all current types of notification (web, basic, image, and
 // list). Future notification types may be handled by other classes, in which
 // case instances of those classes would be returned by the
 // ViewForNotification() factory method below.
 class NotificationView : public MessageView {
  public:
   // Creates appropriate MessageViews for notifications. Those currently are
   // always NotificationView instances but in the future may be instances of
   // other classes, with the class depending on the notification type.
   static MessageView* ViewForNotification(
-      const Notification& notification,
+      Notification* notification,
       NotificationList::Delegate* list_delegate);
 
   NotificationView(NotificationList::Delegate* list_delegate,
-                   const Notification& notification);
+                   Notification* notification);
   virtual ~NotificationView();
 
   // Overridden from View.
   virtual void Layout() OVERRIDE;
   virtual gfx::Size GetPreferredSize() OVERRIDE;
 
   // Overridden from MessageView.
   virtual void SetUpView() OVERRIDE;
   virtual void ButtonPressed(views::Button* sender,
                              const ui::Event& event) OVERRIDE;
 
  private:
   views::View* MakeContentView();
 
   views::View* content_view_;
   std::vector<views::Button*> action_buttons_;
 
   DISALLOW_COPY_AND_ASSIGN(NotificationView);
 };
 
 }  // namespace message_center
 
 #endif // UI_MESSAGE_CENTER_NOTIFICATION_VIEW_H_