Revert of Stop passing const-reference of SWRegistration in all GetRegistrationsCallbacks.

content/browser/notifications/notification_message_filter.h

 // 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.
 
 #ifndef CONTENT_BROWSER_NOTIFICATIONS_NOTIFICATION_MESSAGE_FILTER_H_
 #define CONTENT_BROWSER_NOTIFICATIONS_NOTIFICATION_MESSAGE_FILTER_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 80 matching lines @@
   // Callback to be invoked by the service worker context when the service
   // worker registration was retrieved. Will present the notification to the
   // user when successful.
   void DidFindServiceWorkerRegistration(
       int request_id,
       const GURL& origin,
       const PlatformNotificationData& notification_data,
       const NotificationResources& notification_resources,
       int64_t persistent_notification_id,
       content::ServiceWorkerStatusCode service_worker_status,
-      scoped_refptr<ServiceWorkerRegistration> registration);
+      const scoped_refptr<content::ServiceWorkerRegistration>& registration);
 
   // Callback to be invoked when all notifications belonging to a Service Worker
   // registration have been read from the database. The |success| argument
   // indicates whether the data could be read successfully, whereas the actual
   // notifications will be stored in |notifications|.
   void DidGetNotifications(
       int request_id,
       const std::string& filter_tag,
       bool success,
       const std::vector<NotificationDatabaseData>& notifications);
@@ skipping 26 matching lines @@
   std::map<int, base::Closure> close_closures_;
 
   base::WeakPtrFactory<NotificationMessageFilter> weak_factory_io_;
 
   DISALLOW_COPY_AND_ASSIGN(NotificationMessageFilter);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_NOTIFICATIONS_NOTIFICATION_MESSAGE_FILTER_H_