NotificationController handles an ownership of NotificaitonClient

Source/modules/notifications/NotificationClient.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2011, 2012 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 26 matching lines @@
 #include "wtf/PassRefPtr.h"
 
 namespace WebCore {
 
 class ExecutionContext;
 class Notification;
 
 class NotificationClient {
 
 public:
+    virtual ~NotificationClient() { }
+
     enum Permission {
         PermissionAllowed, // User has allowed notifications
         PermissionNotAllowed, // User has not yet allowed
         PermissionDenied // User has explicitly denied permission
     };
 
     // Requests that a notification be shown.
     virtual bool show(Notification*) = 0;
 
     // Requests that a notification that has already been shown be closed.
     virtual void close(Notification*) = 0;
 
     // Informs the presenter that a Notification object has been destroyed
     // (such as by a page transition). The presenter may continue showing
     // the notification, but must not attempt to call the event handlers.
     virtual void notificationObjectDestroyed(Notification*) = 0;
 
     // Requests user permission to show desktop notifications from a particular
     // script context. The callback parameter should be run when the user has
     // made a decision.
     virtual void requestPermission(ExecutionContext*, PassOwnPtr<NotificationPermissionCallback>) = 0;
 
     // Checks the current level of permission.
     virtual Permission checkPermission(ExecutionContext*) = 0;
-
-protected:
-    virtual ~NotificationClient() { }
 };
 
 } // namespace WebCore
 
 #endif // NotificationClient_h