[Sync] Replace typedef with using.

components/sync_bookmarks/bookmark_model_associator.h

Index: components/sync_bookmarks/bookmark_model_associator.h
diff --git a/components/sync_bookmarks/bookmark_model_associator.h b/components/sync_bookmarks/bookmark_model_associator.h
index 79a3dd77d9c5688e8d0e5af99fe57462c82d250a..63561edcf5c7772d3dd6d343cbc6fb1738efa166 100644
--- a/components/sync_bookmarks/bookmark_model_associator.h
+++ b/components/sync_bookmarks/bookmark_model_associator.h
@@ -113,12 +113,12 @@ class BookmarkModelAssociator
   bool CryptoReadyIfNecessary() override;
 
  private:
-  typedef std::map<int64_t, int64_t> BookmarkIdToSyncIdMap;
-  typedef std::map<int64_t, const bookmarks::BookmarkNode*>
-      SyncIdToBookmarkNodeMap;
-  typedef std::set<int64_t> DirtyAssociationsSyncIds;
-  typedef std::vector<const bookmarks::BookmarkNode*> BookmarkList;
-  typedef std::stack<const bookmarks::BookmarkNode*> BookmarkStack;
+  using BookmarkIdToSyncIdMap = std::map<int64_t, int64_t>;
+  using SyncIdToBookmarkNodeMap =
+      std::map<int64_t, const bookmarks::BookmarkNode*>;
+  using DirtyAssociationsSyncIds = std::set<int64_t>;
+  using BookmarkList = std::vector<const bookmarks::BookmarkNode*>;
+  using BookmarkStack = std::stack<const bookmarks::BookmarkNode*>;
 
   // Add association between native node and sync node to the maps.
   void AddAssociation(const bookmarks::BookmarkNode* node, int64_t sync_id);