Fix virtual/override/final usage in Source/core/html/.

Source/core/html/HTMLImageLoader.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 16 matching lines @@
 #include "core/loader/ImageLoader.h"
 
 namespace blink {
 
 class CORE_EXPORT HTMLImageLoader final : public ImageLoader {
 public:
     static PassOwnPtrWillBeRawPtr<HTMLImageLoader> create(Element* element)
     {
         return adoptPtrWillBeNoop(new HTMLImageLoader(element));
     }
-    virtual ~HTMLImageLoader();
+    ~HTMLImageLoader() override;
 
-    virtual void dispatchLoadEvent() override;
+    void dispatchLoadEvent() override;
 
-    virtual void notifyFinished(Resource*) override;
+    void notifyFinished(Resource*) override;
 
 private:
     Timer<HTMLImageLoader> m_loadFallbackContentTimer;
     void timerFired(Timer<HTMLImageLoader>*);
     explicit HTMLImageLoader(Element*);
-    virtual void noImageResourceToLoad() override;
+    void noImageResourceToLoad() override;
     void ensureFallbackContent();
 };
 
 }
 
 #endif