Use a new Supplement constructor for ServiceWorkerRegistration supplements

third_party/WebKit/Source/modules/background_sync/ServiceWorkerRegistrationSync.cpp

 // Copyright 2015 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 "modules/background_sync/ServiceWorkerRegistrationSync.h"
 
 #include "modules/background_sync/SyncManager.h"
 #include "modules/serviceworkers/ServiceWorkerRegistration.h"
 
 namespace blink {
 
 ServiceWorkerRegistrationSync::ServiceWorkerRegistrationSync(
-    ServiceWorkerRegistration* registration)
-    : m_registration(registration) {}
+    ServiceWorkerRegistration& registration)
+    : Supplement<ServiceWorkerRegistration>(registration) {}
 
 ServiceWorkerRegistrationSync::~ServiceWorkerRegistrationSync() {}
 
 const char* ServiceWorkerRegistrationSync::supplementName() {
   return "ServiceWorkerRegistrationSync";
 }
 
 ServiceWorkerRegistrationSync& ServiceWorkerRegistrationSync::from(
     ServiceWorkerRegistration& registration) {
   ServiceWorkerRegistrationSync* supplement =
       static_cast<ServiceWorkerRegistrationSync*>(
           Supplement<ServiceWorkerRegistration>::from(registration,
                                                       supplementName()));
   if (!supplement) {
-    supplement = new ServiceWorkerRegistrationSync(&registration);
+    supplement = new ServiceWorkerRegistrationSync(registration);
     provideTo(registration, supplementName(), supplement);
   }
   return *supplement;
 }
 
 SyncManager* ServiceWorkerRegistrationSync::sync(
     ServiceWorkerRegistration& registration) {
   return ServiceWorkerRegistrationSync::from(registration).sync();
 }
 
 SyncManager* ServiceWorkerRegistrationSync::sync() {
   if (!m_syncManager)
-    m_syncManager = SyncManager::create(m_registration);
+    m_syncManager = SyncManager::create(supplementable());
   return m_syncManager.get();
 }
 
 DEFINE_TRACE(ServiceWorkerRegistrationSync) {
-  visitor->trace(m_registration);
   visitor->trace(m_syncManager);
   Supplement<ServiceWorkerRegistration>::trace(visitor);
 }
 
 }  // namespace blink