[Sync] Replace typedef with using.

chrome/browser/sync/test/integration/await_match_status_change_checker.h

 // Copyright 2015 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 CHROME_BROWSER_SYNC_TEST_INTEGRATION_AWAIT_MATCH_STATUS_CHANGE_CHECKER_H_
 #define CHROME_BROWSER_SYNC_TEST_INTEGRATION_AWAIT_MATCH_STATUS_CHANGE_CHECKER_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "chrome/browser/sync/test/integration/multi_client_status_change_checker.h"
 
 // Helper class used in the datatype specific AwaitAllModelsMatch
 // implementations. |conditon| should be a datatype specific condition that
 // verifies the state of all the profiles involved in the test.
 class AwaitMatchStatusChangeChecker : public MultiClientStatusChangeChecker {
  public:
-  typedef base::Callback<bool(void)> ExitConditionCallback;
+  using ExitConditionCallback = base::Callback<bool(void)>;
 
   AwaitMatchStatusChangeChecker(const ExitConditionCallback& condition,
                                 const std::string& debug_message);
   ~AwaitMatchStatusChangeChecker() override;
 
   bool IsExitConditionSatisfied() override;
   std::string GetDebugMessage() const override;
 
  private:
   ExitConditionCallback condition_;
   std::string debug_message_;
 };
 
 #endif  // CHROME_BROWSER_SYNC_TEST_INTEGRATION_AWAIT_MATCH_STATUS_CHANGE_CHECKER_H_