[Sync] Replace typedef with using.

components/sync/engine/sync_engine.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_ENGINE_SYNC_ENGINE_H_
 #define COMPONENTS_SYNC_ENGINE_SYNC_ENGINE_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 24 matching lines @@
 class SyncEngineHost;
 class SyncManagerFactory;
 class UnrecoverableErrorHandler;
 
 // The interface into the sync engine, which is the part of sync that performs
 // communication between model types and the sync server. In prod the engine
 // will always live on the sync thread and the object implementing this
 // interface will handle crossing threads if necessary.
 class SyncEngine : public ModelTypeConfigurer {
  public:
-  typedef SyncStatus Status;
-  typedef base::Callback<std::unique_ptr<HttpPostProviderFactory>(
-      CancelationSignal*)>
-      HttpPostProviderFactoryGetter;
+  using Status = SyncStatus;
+  using HttpPostProviderFactoryGetter =
+      base::Callback<std::unique_ptr<HttpPostProviderFactory>(
+          CancelationSignal*)>;
 
   // Utility struct for holding initialization options.
   struct InitParams {
     InitParams();
     InitParams(InitParams&& other);
     ~InitParams();
 
     scoped_refptr<base::SingleThreadTaskRunner> sync_task_runner;
     SyncEngineHost* host = nullptr;
     std::unique_ptr<SyncBackendRegistrar> registrar;
@@ skipping 129 matching lines @@
   // See SyncManager::OnCookieJarChanged.
   virtual void OnCookieJarChanged(bool account_mismatch, bool empty_jar) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SyncEngine);
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_ENGINE_SYNC_ENGINE_H_