Standardize usage of virtual/override/final in ui/

ui/app_list/cocoa/apps_search_results_model_bridge.mm

 // Copyright 2013 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.
 
 #import "ui/app_list/cocoa/apps_search_results_model_bridge.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/strings/sys_string_conversions.h"
 #include "ui/app_list/app_list_model.h"
 #import "ui/app_list/cocoa/apps_search_results_controller.h"
 #include "ui/app_list/search_result.h"
 #include "ui/app_list/search_result_observer.h"
 #import "ui/base/cocoa/menu_controller.h"
 
 namespace app_list {
 
 class AppsSearchResultsModelBridge::ItemObserver : public SearchResultObserver {
  public:
   ItemObserver(AppsSearchResultsModelBridge* bridge, size_t index)
       : bridge_(bridge), row_in_view_(index) {
     // Cache the result, because the results array is updated before notifying
     // observers (which happens before deleting the SearchResult).
     result_ = [bridge_->parent_ results]->GetItemAt(index);
     result_->AddObserver(this);
   }
 
-  virtual ~ItemObserver() {
-    result_->RemoveObserver(this);
-  }
+  ~ItemObserver() override { result_->RemoveObserver(this); }
 
   NSMenu* GetContextMenu() {
     if (!context_menu_controller_) {
       ui::MenuModel* menu_model = result_->GetContextMenuModel();
       if (!menu_model)
         return nil;
 
       context_menu_controller_.reset(
           [[MenuController alloc] initWithModel:menu_model
                          useWithPopUpButtonCell:NO]);
     }
     return [context_menu_controller_ menu];
   }
 
   // SearchResultObserver overrides:
-  virtual void OnIconChanged() override {
+  void OnIconChanged() override {
     bridge_->ReloadDataForItems(row_in_view_, 1);
   }
-  virtual void OnActionsChanged() override {}
-  virtual void OnIsInstallingChanged() override {}
-  virtual void OnPercentDownloadedChanged() override {}
-  virtual void OnItemInstalled() override {}
-  virtual void OnItemUninstalled() override;
+  void OnActionsChanged() override {}
+  void OnIsInstallingChanged() override {}
+  void OnPercentDownloadedChanged() override {}
+  void OnItemInstalled() override {}
+  void OnItemUninstalled() override;
 
  private:
   AppsSearchResultsModelBridge* bridge_;  // Weak. Owns us.
   SearchResult* result_;  // Weak. Owned by AppListModel::SearchResults.
   size_t row_in_view_;
   base::scoped_nsobject<MenuController> context_menu_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(ItemObserver);
 };
 
@@ skipping 64 matching lines @@
 }
 
 void AppsSearchResultsModelBridge::ListItemsChanged(
     size_t start, size_t count) {
   item_observers_.clear();
   ReloadDataForItems(start, count);
   UpdateItemObservers();
 }
 
 }  // namespace app_list