Standardize usage of virtual/override/final in sync/

sync/api/attachments/attachment_store.h

 // Copyright 2014 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 SYNC_API_ATTACHMENTS_ATTACHMENT_STORE_H_
 #define SYNC_API_ATTACHMENTS_ATTACHMENT_STORE_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 97 matching lines @@
   // attachment store is asynchronous, once it finishes |callback| will be
   // called on the thread that called CreateOnDiskStore. |store| parameter of
   // callback is only valid when |result| is SUCCESS.
   static void CreateOnDiskStore(
       const base::FilePath& path,
       const scoped_refptr<base::SequencedTaskRunner>& backend_task_runner,
       const CreateCallback& callback);
 
  protected:
   friend class base::RefCountedThreadSafe<AttachmentStore>;
-  virtual ~AttachmentStore();
+  ~AttachmentStore() override;
 
  private:
   static void CreateOnDiskStoreOnBackendThread(
       const base::FilePath& path,
       const scoped_refptr<base::SequencedTaskRunner>& frontend_task_runner,
       const CreateCallback& callback);
 
   static void CreateBackendDone(
       const Result& result,
       scoped_ptr<AttachmentStoreBase> backend,
       const scoped_refptr<base::SequencedTaskRunner>& backend_task_runner,
       const CreateCallback& callback);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_API_ATTACHMENTS_ATTACHMENT_STORE_H_