[Sync] Replace typedef with using.

components/sync/base/immutable_unittest.cc

 // Copyright (c) 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.
 
 #include "components/sync/base/immutable.h"
 
 #include <cstddef>
 #include <deque>
 #include <list>
 #include <set>
@@ skipping 69 matching lines @@
   // Google-style swap.
   void Swap(TokenBase* other) {
     using std::swap;
     swap(other->core_, core_);
   }
 
  private:
   scoped_refptr<TokenCore> core_;
 };
 
-typedef TokenBase<USE_DEFAULT_SWAP> Token;
-typedef TokenBase<USE_FAST_SWAP_VIA_ADL> ADLToken;
-typedef TokenBase<USE_FAST_SWAP_VIA_SPECIALIZATION> SpecializationToken;
+using Token = TokenBase<USE_DEFAULT_SWAP>;
+using ADLToken = TokenBase<USE_FAST_SWAP_VIA_ADL>;
+using SpecializationToken = TokenBase<USE_FAST_SWAP_VIA_SPECIALIZATION>;
 
 void swap(ADLToken& t1, ADLToken& t2) {
   t1.Swap(&t2);
 }
 
 }  // namespace syncer
 
 // Allowed by the standard (17.4.3.1/1).
 namespace std {
 
@@ skipping 122 matching lines @@
 TEST_F(ImmutableTest, List) {
   RunTokenContainerTest<std::list<Token>, Immutable<std::list<Token>>>("List");
 }
 
 TEST_F(ImmutableTest, Set) {
   RunTokenContainerTest<std::set<Token>, Immutable<std::set<Token>>>("Set");
 }
 
 }  // namespace
 }  // namespace syncer