Use base::MessageLoop in more files.

sync/test/accounts_client/test_accounts_client.h

 // 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.
 
 #ifndef SYNC_TEST_ACCOUNTS_CLIENT_TEST_ACCOUNTS_CLIENT_H_
 #define SYNC_TEST_ACCOUNTS_CLIENT_TEST_ACCOUNTS_CLIENT_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 36 matching lines @@
   // Attempts to release an account via the Test Accounts service. The value
   // of |session| should be one returned from ClaimAccount(). This function
   // is best-effort and fails silently.
   void ReleaseAccount(const AccountSession& session);
 
   // Sends an HTTP POST request to the Test Accounts service.
   virtual bool SendRequest(const GURL& url, string* response);
 
  private:
   GURL CreateGURLWithPath(const string& path);
-  MessageLoopForIO io_loop_;
+  base::MessageLoopForIO io_loop_;
   const string server_;
   const string account_space_;
   vector<string> usernames_;
 };
 
 #endif  // SYNC_TEST_ACCOUNTS_CLIENT_TEST_ACCOUNTS_CLIENT_H_