Standardize usage of virtual/override/final specifiers.

ui/message_center/notification_delegate_unittest.cc

 // 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.
 
 #include "ui/message_center/notification_delegate.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace message_center {
 
 class NotificationDelegateTest : public testing::Test {
  public:
   NotificationDelegateTest();
-  virtual ~NotificationDelegateTest();
+  ~NotificationDelegateTest() override;
 
   void ClickCallback();
 
   int GetClickedCallbackAndReset();
 
  private:
   int callback_count_;
 
   DISALLOW_COPY_AND_ASSIGN(NotificationDelegateTest);
 };
@@ skipping 33 matching lines @@
 
   EXPECT_FALSE(delegate->HasClickedListener());
   delegate->Click();
   EXPECT_EQ(0, GetClickedCallbackAndReset());
 
   delegate->ButtonClick(0);
   EXPECT_EQ(0, GetClickedCallbackAndReset());
 }
 
 }