NotificationController::clientFrom() should return a reference

Source/modules/notifications/NotificationController.h

 /*
 * Copyright (C) 2011 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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
@@ skipping 24 matching lines @@
 class NotificationClient;
 
 class NotificationController FINAL : public Supplement<LocalFrame> {
     WTF_MAKE_NONCOPYABLE(NotificationController);
 public:
     virtual ~NotificationController();
 
     static PassOwnPtr<NotificationController> create(PassOwnPtr<NotificationClient>);
     static const char* supplementName();
     static NotificationController* from(LocalFrame* frame) { return static_cast<NotificationController*>(Supplement<LocalFrame>::from(frame, supplementName())); }
-    static NotificationClient* clientFrom(LocalFrame*);
-
-    NotificationClient* client() { return m_client.get(); }
+    static NotificationClient& clientFrom(LocalFrame*);
 
     virtual void trace(Visitor* visitor) OVERRIDE { Supplement<LocalFrame>::trace(visitor); }
 
 private:
     explicit NotificationController(PassOwnPtr<NotificationClient>);
 
+    NotificationClient& client() { return *m_client; }
+
     OwnPtr<NotificationClient> m_client;
 };
 
 void provideNotification(LocalFrame&, PassOwnPtr<NotificationClient>);
 
 } // namespace WebCore
 
 #endif // NotificationController_h