[Sync] Replace typedef with using.

components/sync/device_info/device_info_sync_service.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 COMPONENTS_SYNC_DEVICE_INFO_DEVICE_INFO_SYNC_SERVICE_H_
 #define COMPONENTS_SYNC_DEVICE_INFO_DEVICE_INFO_SYNC_SERVICE_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 72 matching lines @@
 
   // |local_device_info_provider_| isn't owned.
   const LocalDeviceInfoProvider* const local_device_info_provider_;
 
   // Receives ownership of |sync_processor_| and |error_handler_| in
   // MergeDataAndStartSyncing() and destroy them in StopSyncing().
   std::unique_ptr<SyncChangeProcessor> sync_processor_;
   std::unique_ptr<SyncErrorFactory> error_handler_;
 
   // Cache of all syncable and local data.
-  typedef std::map<std::string, SyncData> SyncDataMap;
+  using SyncDataMap = std::map<std::string, SyncData>;
   SyncDataMap all_data_;
 
   // Registered observers, not owned.
   base::ObserverList<Observer, true> observers_;
 
   // Used to update our local device info once every pulse interval.
   base::OneShotTimer pulse_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceInfoSyncService);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_DEVICE_INFO_DEVICE_INFO_SYNC_SERVICE_H_