Copy build changes to compile mojo::AsyncWaiter to the chromium repo.

mojo/environment/default_run_loop_impl.cc

 // 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.
 
 #include "mojo/environment/default_run_loop_impl.h"
 
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 
 namespace mojo {
 namespace internal {
 
 void InstantiateDefaultRunLoopImpl() {
+  CHECK(!base::MessageLoop::current());
   // Not leaked: accessible from |base::MessageLoop::current()|.
-  new base::MessageLoop();
+  base::MessageLoop* message_loop = new base::MessageLoop();
+  CHECK_EQ(message_loop, base::MessageLoop::current());
 }
 
 void DestroyDefaultRunLoopImpl() {
+  CHECK(base::MessageLoop::current());
   delete base::MessageLoop::current();
+  CHECK(!base::MessageLoop::current());
 }
 
 }  // namespace internal
 }  // namespace mojo