Stop passing const-reference of SWRegistration in all GetRegistrationsCallbacks.

content/browser/loader/navigation_url_loader_impl_core.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_LOADER_NAVIGATION_URL_LOADER_IMPL_CORE_H_
 #define CONTENT_BROWSER_LOADER_NAVIGATION_URL_LOADER_IMPL_CORE_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 56 matching lines @@
                              std::unique_ptr<NavigationData> navigation_data);
 
   // Notifies |loader_| on the UI thread that the request failed.
   void NotifyRequestFailed(bool in_cache, int net_error);
 
  private:
   // Called when done checking whether the navigation has a ServiceWorker
   // registered for it.
   void OnServiceWorkerChecksPerformed(
       ServiceWorkerStatusCode status,
-      const scoped_refptr<ServiceWorkerRegistration>& registration);
+      scoped_refptr<ServiceWorkerRegistration> registration);
 
   base::WeakPtr<NavigationURLLoaderImpl> loader_;
   NavigationResourceHandler* resource_handler_;
   std::unique_ptr<NavigationRequestInfo> request_info_;
   ResourceContext* resource_context_;
 
   base::WeakPtrFactory<NavigationURLLoaderImplCore> factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationURLLoaderImplCore);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_NAVIGATION_URL_LOADER_IMPL_CORE_H_