[Sync] Replace typedef with using.

components/sync/base/model_type.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_BASE_MODEL_TYPE_H_
 #define COMPONENTS_SYNC_BASE_MODEL_TYPE_H_
 
 #include <map>
 #include <memory>
 #include <ostream>
@@ skipping 146 matching lines @@
 
   // If you are adding a new sync datatype that is exposed to the user via the
   // sync preferences UI, be sure to update the list in
   // components/sync/driver/user_selectable_sync_type.h so that the UMA
   // histograms for sync include your new type.  In this case, be sure to also
   // update the UserSelectableTypes() definition in
   // sync/syncable/model_type.cc.
   MODEL_TYPE_COUNT,
 };
 
-typedef EnumSet<ModelType, FIRST_REAL_MODEL_TYPE, LAST_REAL_MODEL_TYPE>
-    ModelTypeSet;
-typedef EnumSet<ModelType, UNSPECIFIED, LAST_REAL_MODEL_TYPE> FullModelTypeSet;
-typedef std::map<ModelType, const char*> ModelTypeNameMap;
+using ModelTypeSet =
+    EnumSet<ModelType, FIRST_REAL_MODEL_TYPE, LAST_REAL_MODEL_TYPE>;
+using FullModelTypeSet = EnumSet<ModelType, UNSPECIFIED, LAST_REAL_MODEL_TYPE>;
+using ModelTypeNameMap = std::map<ModelType, const char*>;
 
 inline ModelType ModelTypeFromInt(int i) {
   DCHECK_GE(i, 0);
   DCHECK_LT(i, MODEL_TYPE_COUNT);
   return static_cast<ModelType>(i);
 }
 
 // Used by tests outside of sync/.
 void AddDefaultFieldValue(ModelType datatype,
                           sync_pb::EntitySpecifics* specifics);
@@ skipping 167 matching lines @@
 
 // Returns true if |model_type| supports parent-child hierarchy or entries.
 bool TypeSupportsHierarchy(ModelType model_type);
 
 // Returns true if |model_type| supports ordering of sibling entries.
 bool TypeSupportsOrdering(ModelType model_type);
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_BASE_MODEL_TYPE_H_