Remove remaining calls to deprecated MessageLoop methods on Mac.

base/ios/weak_nsobject_unittest.mm

Index: base/ios/weak_nsobject_unittest.mm
diff --git a/base/ios/weak_nsobject_unittest.mm b/base/ios/weak_nsobject_unittest.mm
index f7abfa13b01945c1a840376281076188ecdaf986..ba85217d277b67f5a29010b8a5bdec31b7c0025b 100644
--- a/base/ios/weak_nsobject_unittest.mm
+++ b/base/ios/weak_nsobject_unittest.mm
@@ -6,6 +6,7 @@
 #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"
@@ -129,7 +130,7 @@ TEST(WeakNSObjectTest, WeakNSObjectCopyOnOtherThread) {
   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]);