Revert of base: Remove use of MessageLoopProxy

chromeos/login/auth/online_attempt_host.h

 // 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.
 
 #ifndef CHROMEOS_LOGIN_AUTH_ONLINE_ATTEMPT_HOST_H_
 #define CHROMEOS_LOGIN_AUTH_ONLINE_ATTEMPT_HOST_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chromeos/chromeos_export.h"
 #include "chromeos/login/auth/auth_attempt_state_resolver.h"
 #include "chromeos/login/auth/user_context.h"
 
-namespace base {
-// TODO(skyostil): Migrate to SingleThreadTaskRunner (crbug.com/465354).
-class MessageLoopProxy;
-}
-
 namespace net {
 class URLRequestContextGetter;
 }
 
 namespace chromeos {
 
 class AuthAttemptState;
 class OnlineAttempt;
 class UserContext;
 
@@ skipping 35 matching lines @@
   scoped_ptr<OnlineAttempt> online_attempt_;
   scoped_ptr<AuthAttemptState> state_;
   base::WeakPtrFactory<OnlineAttemptHost> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(OnlineAttemptHost);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_LOGIN_AUTH_ONLINE_ATTEMPT_HOST_H_