[Sync] Replace typedef with using.

components/sync/engine_impl/sync_manager_impl.h

 // Copyright 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 COMPONENTS_SYNC_ENGINE_IMPL_SYNC_MANAGER_IMPL_H_
 #define COMPONENTS_SYNC_ENGINE_IMPL_SYNC_MANAGER_IMPL_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 182 matching lines @@
 
     int total_count;
     std::string payload;
 
     // Returned pointer owned by the caller.
     base::DictionaryValue* ToValue() const;
   };
 
   base::TimeDelta GetNudgeDelayTimeDelta(const ModelType& model_type);
 
-  typedef std::map<ModelType, NotificationInfo> NotificationInfoMap;
+  using NotificationInfoMap = std::map<ModelType, NotificationInfo>;
 
   // Determine if the parents or predecessors differ between the old and new
   // versions of an entry.  Note that a node's index may change without its
   // UNIQUE_POSITION changing if its sibling nodes were changed.  To handle such
   // cases, we rely on the caller to treat a position update on any sibling as
   // updating the positions of all siblings.
   bool VisiblePositionsDiffer(
       const syncable::EntryKernelMutation& mutation) const;
 
   // Determine if any of the fields made visible to clients of the Sync API
@@ skipping 70 matching lines @@
   // A multi-purpose status watch object that aggregates stats from various
   // sync components.
   AllStatus allstatus_;
 
   // Each element of this map is a store of change records produced by
   // HandleChangeEventFromSyncer during the CALCULATE_CHANGES step. The changes
   // are grouped by model type, and are stored here in tree order to be
   // forwarded to the observer slightly later, at the TRANSACTION_ENDING step
   // by HandleTransactionEndingChangeEvent. The list is cleared after observer
   // finishes processing.
-  typedef std::map<int, ImmutableChangeRecordList> ChangeRecordMap;
+  using ChangeRecordMap = std::map<int, ImmutableChangeRecordList>;
   ChangeRecordMap change_records_;
 
   SyncManager::ChangeDelegate* change_delegate_;
 
   // Set to true once Init has been called.
   bool initialized_;
 
   bool observing_network_connectivity_changes_;
 
   // Map used to store the notification info to be displayed in
@@ skipping 18 matching lines @@
   std::unique_ptr<SyncEncryptionHandlerImpl> sync_encryption_handler_;
 
   base::WeakPtrFactory<SyncManagerImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncManagerImpl);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_ENGINE_IMPL_SYNC_MANAGER_IMPL_H_