Standardize usage of virtual/override/final in chrome/browser/browsing_data/

chrome/browser/browsing_data/browsing_data_database_helper.h

 // 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.
 
 #ifndef CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_DATABASE_HELPER_H_
 #define CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_DATABASE_HELPER_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 116 matching lines @@
   // True if no databases are currently stored.
   bool empty() const;
 
   // Returns the number of currently stored databases.
   size_t GetDatabaseCount() const;
 
   // Returns the current list of web databases.
   const std::set<PendingDatabaseInfo>& GetPendingDatabaseInfo();
 
   // BrowsingDataDatabaseHelper implementation.
-  virtual void StartFetching(
-      const base::Callback<void(const std::list<DatabaseInfo>&)>& callback)
-          override;
-  virtual void DeleteDatabase(const std::string& origin_identifier,
-                              const std::string& name) override;
+  void StartFetching(const base::Callback<void(const std::list<DatabaseInfo>&)>&
+                         callback) override;
+  void DeleteDatabase(const std::string& origin_identifier,
+                      const std::string& name) override;
 
  private:
-  virtual ~CannedBrowsingDataDatabaseHelper();
+  ~CannedBrowsingDataDatabaseHelper() override;
 
   std::set<PendingDatabaseInfo> pending_database_info_;
 
   DISALLOW_COPY_AND_ASSIGN(CannedBrowsingDataDatabaseHelper);
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_DATABASE_HELPER_H_