Remove remaining calls to deprecated MessageLoop methods on Mac.

base/ios/weak_nsobject_unittest.mm

 // Copyright 2013 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 "base/bind.h"
 #include "base/ios/weak_nsobject.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 namespace {
 
 TEST(WeakNSObjectTest, WeakNSObject) {
   scoped_nsobject<NSObject> p1([[NSObject alloc] init]);
   WeakNSObject<NSObject> w1(p1);
@@ skipping 103 matching lines @@
   Thread other_thread("WeakNSObjectCopyOnOtherThread");
   other_thread.Start();
 
   scoped_nsobject<NSMutableData> data([[NSMutableData alloc] init]);
   WeakNSObject<NSMutableData> weak(data);
 
   scoped_refptr<SingleThreadTaskRunner> runner = loop.task_runner();
   other_thread.task_runner()->PostTask(
       FROM_HERE, Bind(&CopyWeakNSObjectAndPost, weak, runner));
   other_thread.Stop();
-  loop.RunUntilIdle();
+  RunLoop().RunUntilIdle();
 
   // Check that TouchWeakData was called and the object touched twice.
   EXPECT_EQ(2u, [data length]);
 }
 
 }  // namespace
 }  // namespace base