Standardize usage of virtual/override/final specifiers.

chrome/browser/ui/views/location_bar/search_button.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 CHROME_BROWSER_UI_VIEWS_LOCATION_BAR_SEARCH_BUTTON_H_
 #define CHROME_BROWSER_UI_VIEWS_LOCATION_BAR_SEARCH_BUTTON_H_
 
 #include "ui/views/controls/button/label_button.h"
 
 // A blue button shown at the end of the omnibox that holds either a search or
 // navigation icon based on the current omnibox text.  This is something like a
 // cross between a historical browser "Go" button and the Google "search"
 // button.
 class SearchButton : public views::LabelButton {
  public:
   explicit SearchButton(views::ButtonListener* listener);
-  virtual ~SearchButton();
+  ~SearchButton() override;
 
   // Updates the search button icon to a search icon if |is_search| is true, or
   // a navigation icon otherwise.
   void UpdateIcon(bool is_search);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SearchButton);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_LOCATION_BAR_SEARCH_BUTTON_H_