Notificaitons refactor step 2

ui/message_center/message_simple_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_MESSAGE_SIMPLE_VIEW_H_
 #define UI_MESSAGE_CENTER_MESSAGE_SIMPLE_VIEW_H_
 
 #include "ui/message_center/message_view.h"
 #include "ui/message_center/notification_list.h"
 
 namespace message_center {
 
-struct Notification;
+class Notification;
 
 // A simple view for a notification entry (icon + message + buttons).
 class MessageSimpleView : public MessageView {
  public:
   MessageSimpleView(NotificationList::Delegate* list_delegate,
-                    const Notification& notification);
+                    Notification* notification);
   virtual ~MessageSimpleView();
 
   // Overridden from MessageView:
   virtual void SetUpView() OVERRIDE;
   virtual void ButtonPressed(views::Button* sender,
                              const ui::Event& event) OVERRIDE;
 
  protected:
   // Overridden from views::View:
   virtual gfx::Size GetPreferredSize() OVERRIDE;
   virtual void Layout() OVERRIDE;
 
   MessageSimpleView();
 
  private:
   scoped_ptr<views::ImageButton> old_style_close_button_;
   scoped_ptr<views::View> content_view_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageSimpleView);
 };
 
 }  // namespace message_center
 
 #endif // UI_MESSAGE_CENTER_MESSAGE_SIMPLE_VIEW_H_