Pass implementation object to supplemental classes by reference

Source/modules/serviceworkers/NavigatorServiceWorker.cpp

 // Copyright 2014 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.
 
 #include "config.h"
 #include "modules/serviceworkers/NavigatorServiceWorker.h"
 
 #include "core/frame/Navigator.h"
 #include "modules/serviceworkers/ServiceWorkerContainer.h"
 
 namespace WebCore {
 
-NavigatorServiceWorker::NavigatorServiceWorker(Navigator* navigator)
-    : DOMWindowProperty(navigator->frame())
+NavigatorServiceWorker::NavigatorServiceWorker(Navigator& navigator)
+    : DOMWindowProperty(navigator.frame())
 {
 }
 
 NavigatorServiceWorker::~NavigatorServiceWorker()
 {
 }
 
-NavigatorServiceWorker* NavigatorServiceWorker::from(Navigator* navigator)
+NavigatorServiceWorker& NavigatorServiceWorker::from(Navigator& navigator)
 {
     NavigatorServiceWorker* supplement = toNavigatorServiceWorker(navigator);
     if (!supplement) {
         supplement = new NavigatorServiceWorker(navigator);
         provideTo(navigator, supplementName(), adoptPtr(supplement));
     }
-    return supplement;
+    return *supplement;
 }
 
 const char* NavigatorServiceWorker::supplementName()
 {
     return "NavigatorServiceWorker";
 }
 
-ServiceWorkerContainer* NavigatorServiceWorker::serviceWorker(Navigator* navigator)
+ServiceWorkerContainer* NavigatorServiceWorker::serviceWorker(Navigator& navigator)
 {
-    return NavigatorServiceWorker::from(navigator)->serviceWorker();
+    return NavigatorServiceWorker::from(navigator).serviceWorker();
 }
 
 ServiceWorkerContainer* NavigatorServiceWorker::serviceWorker()
 {
     if (!m_serviceWorker && frame())
         m_serviceWorker = ServiceWorkerContainer::create();
     return m_serviceWorker.get();
 }
 
 } // namespace WebCore