Stop passing const-reference of SWRegistration in all GetRegistrationsCallbacks.

content/browser/background_sync/background_sync_browsertest.cc

 // 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 <stdint.h>
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 72 matching lines @@
     }
   }
   ADD_FAILURE() << "Registration should exist";
 }
 
 void RegistrationPendingDidGetSWRegistration(
     const scoped_refptr<BackgroundSyncContext> sync_context,
     const std::string& tag,
     const base::Callback<void(bool)>& callback,
     ServiceWorkerStatusCode status,
-    const scoped_refptr<ServiceWorkerRegistration>& registration) {
+    scoped_refptr<ServiceWorkerRegistration> registration) {
   ASSERT_EQ(SERVICE_WORKER_OK, status);
   int64_t service_worker_id = registration->id();
   BackgroundSyncManager* sync_manager = sync_context->background_sync_manager();
   sync_manager->GetRegistrations(
       service_worker_id,
       base::Bind(&RegistrationPendingDidGetSyncRegistration, tag, callback));
 }
 
 void RegistrationPendingOnIOThread(
     const scoped_refptr<BackgroundSyncContext> sync_context,
@@ skipping 576 matching lines @@
 IN_PROC_BROWSER_TEST_F(BackgroundSyncBrowserTest,
                        RegisterFromServiceWorkerWithoutMainFrameHost) {
   std::string script_result;
   EXPECT_TRUE(
       RegisterFromCrossOriginFrame(kRegisterSyncFromSWURL, &script_result));
   EXPECT_EQ(BuildExpectedResult("frame", "failed to register sync"),
             script_result);
 }
 
 }  // namespace content