Standardize usage of virtual/override/final in ui/

ui/app_list/cocoa/apps_grid_controller_unittest.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.
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/utf_string_conversions.h"
 #include "skia/ext/skia_utils_mac.h"
 #import "testing/gtest_mac.h"
 #include "ui/app_list/app_list_constants.h"
@@ skipping 127 matching lines @@
         menu_model_(NULL),
         menu_ready_(true) {
     SetName(id);
     menu_model_.AddItem(0, base::UTF8ToUTF16("Menu For: " + id));
   }
 
   void SetMenuReadyForTesting(bool ready) {
     menu_ready_ = ready;
   }
 
-  virtual ui::MenuModel* GetContextMenuModel() override {
+  ui::MenuModel* GetContextMenuModel() override {
     if (!menu_ready_)
       return NULL;
 
     return &menu_model_;
   }
 
  private:
   ui::SimpleMenuModel menu_model_;
   bool menu_ready_;
 
@@ skipping 823 matching lines @@
   // Test that a button being held down with the left button does not also show
   // a context menu.
   [GetItemViewAt(0) highlight:YES];
   EXPECT_FALSE([page menuForEvent:mouse_at_cell_0]);
   [GetItemViewAt(0) highlight:NO];
   EXPECT_TRUE([page menuForEvent:mouse_at_cell_0]);
 }
 
 }  // namespace test
 }  // namespace app_list