Standardize usage of virtual/override/final specifiers.

chrome/browser/download/download_history_unittest.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 <vector>
 
 #include "base/memory/weak_ptr.h"
 #include "base/rand_util.h"
 #include "base/stl_util.h"
 #include "chrome/browser/download/download_history.h"
@@ skipping 185 matching lines @@
  public:
   // Generic callback that receives a pointer to a StrictMockDownloadItem.
   typedef base::Callback<void(content::MockDownloadItem*)> DownloadItemCallback;
 
   DownloadHistoryTest()
       : ui_thread_(content::BrowserThread::UI, &loop_),
         manager_(new content::MockDownloadManager()),
         history_(NULL),
         manager_observer_(NULL),
         download_created_index_(0) {}
-  virtual ~DownloadHistoryTest() {
-    STLDeleteElements(&items_);
-  }
+  ~DownloadHistoryTest() override { STLDeleteElements(&items_); }
 
  protected:
-  virtual void TearDown() override {
-    download_history_.reset();
-  }
+  void TearDown() override { download_history_.reset(); }
 
   content::MockDownloadManager& manager() { return *manager_.get(); }
   content::MockDownloadItem& item(size_t index) { return *items_[index]; }
   DownloadHistory* download_history() { return download_history_.get(); }
 
   void SetManagerObserver(
       content::DownloadManager::Observer* manager_observer) {
     manager_observer_ = manager_observer;
   }
   content::DownloadManager::Observer* manager_observer() {
@@ skipping 637 matching lines @@
   FinishCreateDownload();
   EXPECT_TRUE(DownloadHistory::IsPersisted(&item(0)));
 
   // ItemAdded should call OnDownloadUpdated, which should detect that the item
   // changed while it was being added and call UpdateDownload immediately.
   info.opened = true;
   ExpectDownloadUpdated(info);
 }
 
 }  // anonymous namespace