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

chrome/browser/browsing_data/browsing_data_file_system_helper.cc

 // 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.
 
 #include "chrome/browser/browsing_data/browsing_data_file_system_helper.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
@@ skipping 16 matching lines @@
 namespace {
 
 // An implementation of the BrowsingDataFileSystemHelper interface that pulls
 // data from a given |filesystem_context| and returns a list of FileSystemInfo
 // items to a client.
 class BrowsingDataFileSystemHelperImpl : public BrowsingDataFileSystemHelper {
  public:
   // BrowsingDataFileSystemHelper implementation
   explicit BrowsingDataFileSystemHelperImpl(
       storage::FileSystemContext* filesystem_context);
-  virtual void StartFetching(const base::Callback<
-      void(const std::list<FileSystemInfo>&)>& callback) override;
-  virtual void DeleteFileSystemOrigin(const GURL& origin) override;
+  void StartFetching(
+      const base::Callback<void(const std::list<FileSystemInfo>&)>& callback)
+      override;
+  void DeleteFileSystemOrigin(const GURL& origin) override;
 
  private:
-  virtual ~BrowsingDataFileSystemHelperImpl();
+  ~BrowsingDataFileSystemHelperImpl() override;
 
   // Enumerates all filesystem files, storing the resulting list into
   // file_system_file_ for later use. This must be called on the file
   // task runner.
   void FetchFileSystemInfoInFileThread();
 
   // Triggers the success callback as the end of a StartFetching workflow. This
   // must be called on the UI thread.
   void NotifyOnUIThread();
 
@@ skipping 188 matching lines @@
 }
 
 void CannedBrowsingDataFileSystemHelper::StartFetching(
     const base::Callback<void(const std::list<FileSystemInfo>&)>& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(!callback.is_null());
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE, base::Bind(callback, file_system_info_));
 }