Remove remaining calls to deprecated MessageLoop methods.

remoting/protocol/authenticator_test_base.h

 // Copyright (c) 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.
 
 #ifndef REMOTING_PROTOCOL_AUTHENTICATOR_TEST_BASE_H_
 #define REMOTING_PROTOCOL_AUTHENTICATOR_TEST_BASE_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 32 matching lines @@
                                        bool sender_started,
                                        bool receiver_srated);
   void SetUp() override;
   void RunAuthExchange();
   void RunHostInitiatedAuthExchange();
   void RunChannelAuth(bool expected_fail);
 
   void OnHostConnected(int error, std::unique_ptr<P2PStreamSocket> socket);
   void OnClientConnected(int error, std::unique_ptr<P2PStreamSocket> socket);
 
-  base::MessageLoop message_loop_;
-
   scoped_refptr<RsaKeyPair> key_pair_;
   std::string host_public_key_;
   std::string host_cert_;
   std::unique_ptr<Authenticator> host_;
   std::unique_ptr<Authenticator> client_;
   std::unique_ptr<FakeStreamSocket> client_fake_socket_;
   std::unique_ptr<FakeStreamSocket> host_fake_socket_;
   std::unique_ptr<ChannelAuthenticator> client_auth_;
   std::unique_ptr<ChannelAuthenticator> host_auth_;
   MockChannelDoneCallback client_callback_;
   MockChannelDoneCallback host_callback_;
   std::unique_ptr<P2PStreamSocket> client_socket_;
   std::unique_ptr<P2PStreamSocket> host_socket_;
 
+ private:
+  base::MessageLoop message_loop_;
+
   DISALLOW_COPY_AND_ASSIGN(AuthenticatorTestBase);
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_AUTHENTICATOR_TEST_BASE_H_