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

chrome/browser/history/history_database.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_HISTORY_HISTORY_DATABASE_H_
 #define CHROME_BROWSER_HISTORY_HISTORY_DATABASE_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
@@ skipping 47 matching lines @@
     }
    private:
     HistoryDatabase* db_;
   };
 
   // Must call Init() to complete construction. Although it can be created on
   // any thread, it must be destructed on the history thread for proper
   // database cleanup.
   HistoryDatabase();
 
-  virtual ~HistoryDatabase();
+  ~HistoryDatabase() override;
 
   // Call before Init() to set the error callback to be used for the
   // underlying database connection.
   void set_error_callback(
       const sql::Connection::ErrorCallback& error_callback) {
     error_callback_ = error_callback;
   }
 
   // Must call this function to complete initialization. Will return
   // sql::INIT_OK on success. Otherwise, no other function should be called. You
@@ skipping 76 matching lines @@
  private:
 #if defined(OS_ANDROID)
   // AndroidProviderBackend uses the |db_|.
   friend class AndroidProviderBackend;
   FRIEND_TEST_ALL_PREFIXES(AndroidURLsMigrationTest, MigrateToVersion22);
 #endif
   friend class ::HistoryQuickProviderTest;
   friend class InMemoryURLIndexTest;
 
   // Overridden from URLDatabase:
-  virtual sql::Connection& GetDB() override;
+  sql::Connection& GetDB() override;
 
   // Migration -----------------------------------------------------------------
 
   // Makes sure the version is up-to-date, updating if necessary. If the
   // database is too old to migrate, the user will be notified. Returns
   // sql::INIT_OK iff  the DB is up-to-date and ready for use.
   //
   // This assumes it is called from the init function inside a transaction. It
   // may commit the transaction and start a new one if migration requires it.
   sql::InitStatus EnsureCurrentVersion();
@@ skipping 11 matching lines @@
   sql::MetaTable meta_table_;
 
   base::Time cached_early_expiration_threshold_;
 
   DISALLOW_COPY_AND_ASSIGN(HistoryDatabase);
 };
 
 }  // namespace history
 
 #endif  // CHROME_BROWSER_HISTORY_HISTORY_DATABASE_H_