Standardize usage of virtual/override/final specifiers.

ui/views/controls/button/custom_button_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 "ui/views/controls/button/custom_button.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/aura/test/test_cursor_client.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_event_dispatcher.h"
@@ skipping 11 matching lines @@
 namespace views {
 
 namespace {
 
 class TestCustomButton : public CustomButton {
  public:
   explicit TestCustomButton(ButtonListener* listener)
       : CustomButton(listener) {
   }
 
-  virtual ~TestCustomButton() {}
+  ~TestCustomButton() override {}
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestCustomButton);
 };
 
 void PerformGesture(CustomButton* button, ui::EventType event_type) {
   ui::GestureEventDetails gesture_details(event_type);
   base::TimeDelta time_stamp = base::TimeDelta::FromMicroseconds(0);
   ui::GestureEvent gesture_event(0, 0, 0, time_stamp, gesture_details);
   button->OnGestureEvent(&gesture_event);
@@ skipping 119 matching lines @@
   EXPECT_FALSE(CustomButton::AsCustomButton(&label));
 
   Link link(text);
   EXPECT_FALSE(CustomButton::AsCustomButton(&link));
 
   Textfield textfield;
   EXPECT_FALSE(CustomButton::AsCustomButton(&textfield));
 }
 
 }  // namespace views