[Sync] Replace typedef with using.

components/sync/device_info/local_device_info_provider.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_LOCAL_DEVICE_INFO_PROVIDER_H_
 #define COMPONENTS_SYNC_DEVICE_INFO_LOCAL_DEVICE_INFO_PROVIDER_H_
 
 #include <memory>
 #include <string>
 
 #include "base/callback_list.h"
 
 namespace base {
 class TaskRunner;
 }
 
 namespace syncer {
 
 class DeviceInfo;
 
 // Interface for providing sync specific information about the
 // local device.
 class LocalDeviceInfoProvider {
  public:
-  typedef base::CallbackList<void(void)>::Subscription Subscription;
+  using Subscription = base::CallbackList<void(void)>::Subscription;
 
   virtual ~LocalDeviceInfoProvider() {}
 
   // Returns sync's representation of the local device info, or nullptr if the
   // device info is unavailable. The returned object is fully owned by
   // LocalDeviceInfoProvider; it must not be freed by the caller and should not
   // be stored.
   virtual const DeviceInfo* GetLocalDeviceInfo() const = 0;
 
   // Constructs a user agent string (ASCII) suitable for use by the syncapi
@@ skipping 19 matching lines @@
   virtual std::unique_ptr<Subscription> RegisterOnInitializedCallback(
       const base::Closure& callback) = 0;
 
   // Clears all cached data, returning to an uninitialized state.
   virtual void Clear() = 0;
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_DEVICE_INFO_LOCAL_DEVICE_INFO_PROVIDER_H_