[Sync] Replace typedef with using.

components/sync_sessions/favicon_cache.h

 // Copyright 2013 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_SESSIONS_FAVICON_CACHE_H_
 #define COMPONENTS_SYNC_SESSIONS_FAVICON_CACHE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 105 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(SyncFaviconCacheTest, HistorySubsetClear);
 
   // Functor for ordering SyncedFaviconInfo objects by recency;
   struct FaviconRecencyFunctor {
     bool operator()(const linked_ptr<SyncedFaviconInfo>& lhs,
                     const linked_ptr<SyncedFaviconInfo>& rhs) const;
   };
 
 
   // Map of favicon url to favicon image.
-  typedef std::map<GURL, linked_ptr<SyncedFaviconInfo> > FaviconMap;
-  typedef std::set<linked_ptr<SyncedFaviconInfo>,
-                   FaviconRecencyFunctor> RecencySet;
+  using FaviconMap = std::map<GURL, linked_ptr<SyncedFaviconInfo>>;
+  using RecencySet =
+      std::set<linked_ptr<SyncedFaviconInfo>, FaviconRecencyFunctor>;
   // Map of page url to task id (for favicon loading).
-  typedef std::map<GURL, base::CancelableTaskTracker::TaskId> PageTaskMap;
+  using PageTaskMap = std::map<GURL, base::CancelableTaskTracker::TaskId>;
   // Map of page url to favicon url.
-  typedef std::map<GURL, GURL> PageFaviconMap;
+  using PageFaviconMap = std::map<GURL, GURL>;
 
   // Helper method to perform OnReceivedSyncFavicon work without worrying about
   // whether caller holds a sync transaction.
   void OnReceivedSyncFaviconImpl(const GURL& icon_url,
                                  const std::string& icon_bytes,
                                  int64_t visit_time_ms);
 
   // Callback method to store a tab's favicon into its sync node once it becomes
   // available. Does nothing if no favicon data was available.
   void OnFaviconDataAvailable(
@@ skipping 103 matching lines @@
 
   // Weak pointer factory for favicon loads.
   base::WeakPtrFactory<FaviconCache> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FaviconCache);
 };
 
 }  // namespace sync_sessions
 
 #endif  // COMPONENTS_SYNC_SESSIONS_FAVICON_CACHE_H_