[Sync] Replace typedef with using.

components/sync/engine_impl/model_type_registry.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_ENGINE_IMPL_MODEL_TYPE_REGISTRY_H_
 #define COMPONENTS_SYNC_ENGINE_IMPL_MODEL_TYPE_REGISTRY_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 13 matching lines @@
 
 namespace syncer {
 
 class CommitContributor;
 class DataTypeDebugInfoEmitter;
 class DirectoryCommitContributor;
 class DirectoryUpdateHandler;
 class ModelTypeWorker;
 class UpdateHandler;
 
-typedef std::map<ModelType, UpdateHandler*> UpdateHandlerMap;
-typedef std::map<ModelType, CommitContributor*> CommitContributorMap;
+using UpdateHandlerMap = std::map<ModelType, UpdateHandler*>;
+using CommitContributorMap = std::map<ModelType, CommitContributor*>;
 
 // Keeps track of the sets of active update handlers and commit contributors.
 class ModelTypeRegistry : public ModelTypeConnector,
                           public SyncEncryptionHandler::Observer {
  public:
   ModelTypeRegistry(const std::vector<scoped_refptr<ModelSafeWorker>>& workers,
                     UserShare* user_share,
                     NudgeHandler* nudge_handler,
                     const UssMigrator& uss_migrator);
   ~ModelTypeRegistry() override;
@@ skipping 53 matching lines @@
   void RegisterDirectoryTypeDebugInfoObserver(TypeDebugInfoObserver* observer);
   void UnregisterDirectoryTypeDebugInfoObserver(
       TypeDebugInfoObserver* observer);
   bool HasDirectoryTypeDebugInfoObserver(
       const TypeDebugInfoObserver* observer) const;
   void RequestEmitDebugInfo();
 
   base::WeakPtr<ModelTypeConnector> AsWeakPtr();
 
  private:
-  typedef std::map<ModelType, std::unique_ptr<DataTypeDebugInfoEmitter>>
-      DataTypeDebugInfoEmitterMap;
+  using DataTypeDebugInfoEmitterMap =
+      std::map<ModelType, std::unique_ptr<DataTypeDebugInfoEmitter>>;
 
   void OnEncryptionStateChanged();
 
   // DebugInfoEmitters are never deleted. Returns an existing one if we have it.
   DataTypeDebugInfoEmitter* GetEmitter(ModelType type);
 
   ModelTypeSet GetEnabledNonBlockingTypes() const;
   ModelTypeSet GetEnabledDirectoryTypes() const;
 
   syncable::Directory* directory() const {
@@ skipping 44 matching lines @@
   base::ObserverList<TypeDebugInfoObserver> type_debug_info_observers_;
 
   base::WeakPtrFactory<ModelTypeRegistry> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ModelTypeRegistry);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_ENGINE_IMPL_MODEL_TYPE_REGISTRY_H_