Remove calls to deprecated MessageLoop methods in components.

components/sync_driver/glue/sync_backend_registrar_unittest.cc

 // Copyright 2012 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 "components/sync_driver/glue/sync_backend_registrar.h"
 
 #include "base/location.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "components/sync_driver/change_processor_mock.h"
@@ skipping 102 matching lines @@
     sync_thread_ = registrar_->sync_thread();
   }
 
   void TearDown() override {
     registrar_->RequestWorkerStopOnUIThread();
     test_user_share_.TearDown();
     sync_thread_->task_runner()->PostTask(
         FROM_HERE, base::Bind(&SyncBackendRegistrar::Shutdown,
                               base::Unretained(registrar_.release())));
     sync_thread_->WaitUntilThreadStarted();
-    sync_thread_->message_loop()->RunUntilIdle();
+    base::RunLoop().RunUntilIdle();
   }
 
   void ExpectRoutingInfo(
       SyncBackendRegistrar* registrar,
       const syncer::ModelSafeRoutingInfo& expected_routing_info) {
     syncer::ModelSafeRoutingInfo routing_info;
     registrar->GetModelSafeRoutingInfo(&routing_info);
     EXPECT_EQ(expected_routing_info, routing_info);
   }
 
@@ skipping 314 matching lines @@
 
   sync_thread->task_runner()->PostTask(
       FROM_HERE, base::Bind(&SyncBackendRegistrar::Shutdown,
                             base::Unretained(registrar.release())));
 
   // Make sure the thread starts running.
   sync_thread->WaitUntilThreadStarted();
 
   // The test verifies that the sync thread doesn't block because
   // of the blocked DB thread and can finish the shutdown.
-  sync_thread->message_loop()->RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
 
   db_thread_lock_.Release();
 
   // Run the main thread loop until all workers have been removed and the
   // registrar destroyed.
   run_loop_.Run();
 }
 
 }  // namespace
 
 }  // namespace browser_sync