views: Extract Widget observer into its own header file.

chrome/browser/chromeos/status/data_promo_notification.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_CHROMEOS_STATUS_DATA_PROMO_NOTIFICATION_H_
 #define CHROME_BROWSER_CHROMEOS_STATUS_DATA_PROMO_NOTIFICATION_H_
 
 #include "base/basictypes.h"
 #include "base/memory/weak_ptr.h"
-#include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_observer.h"
 
 class PrefService;
 
 namespace views {
 class View;
-}  // namespace views
+}
 
 namespace chromeos {
 class MessageBubble;
 class MessageBubbleLinkListener;
 class NetworkLibrary;
 
-class DataPromoNotification : public views::Widget::Observer {
+class DataPromoNotification : public views::WidgetObserver {
  public:
   DataPromoNotification();
   virtual ~DataPromoNotification();
 
   static void RegisterPrefs(PrefService* local_state);
 
   const std::string& deal_info_url() const { return deal_info_url_; }
   const std::string& deal_topup_url() const { return deal_topup_url_; }
 
   // Shows 3G promo notification if needed.
   void ShowOptionalMobileDataPromoNotification(
       NetworkLibrary* cros,
       views::View* host,
       MessageBubbleLinkListener* listener);
 
   // Closes message bubble.
   void CloseNotification();
 
  private:
-  // Overridden from views::Widget::Observer.
+  // Overridden from views::WidgetObserver:
   virtual void OnWidgetClosing(views::Widget* widget) OVERRIDE;
 
   // Notification bubble for 3G promo.
   MessageBubble* mobile_data_bubble_;
 
   // True if check for promo needs to be done,
   // otherwise just ignore it for current session.
   bool check_for_promo_;
 
   // Current carrier deal info URL.
   std::string deal_info_url_;
 
   // Current carrier deal top-up URL.
   std::string deal_topup_url_;
 
   // Factory for delaying showing promo notification.
   base::WeakPtrFactory<DataPromoNotification> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DataPromoNotification);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_STATUS_DATA_PROMO_NOTIFICATION_H_