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

Source/core/html/HTMLSourceElement.h

 /*
  * Copyright (C) 2007, 2008, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 23 matching lines @@
 
 template<typename T> class EventSender;
 typedef EventSender<HTMLSourceElement> SourceEventSender;
 
 class HTMLSourceElement final : public HTMLElement {
     DEFINE_WRAPPERTYPEINFO();
 public:
     class Listener;
 
     DECLARE_NODE_FACTORY(HTMLSourceElement);
-    virtual ~HTMLSourceElement();
+    ~HTMLSourceElement() override;
 
     const AtomicString& type() const;
     void setSrc(const String&);
     void setType(const AtomicString&);
 
     void scheduleErrorEvent();
     void cancelPendingErrorEvent();
 
     void dispatchPendingEvent(SourceEventSender*);
 
     bool mediaQueryMatches() const;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit HTMLSourceElement(Document&);
 
-    virtual void didMoveToNewDocument(Document& oldDocument) override;
+    void didMoveToNewDocument(Document& oldDocument) override;
 
-    virtual InsertionNotificationRequest insertedInto(ContainerNode*) override;
-    virtual void removedFrom(ContainerNode*) override;
-    virtual bool isURLAttribute(const Attribute&) const override;
-    virtual void parseAttribute(const QualifiedName&, const AtomicString&) override;
+    InsertionNotificationRequest insertedInto(ContainerNode*) override;
+    void removedFrom(ContainerNode*) override;
+    bool isURLAttribute(const Attribute&) const override;
+    void parseAttribute(const QualifiedName&, const AtomicString&) override;
 
     void notifyMediaQueryChanged();
     void createMediaQueryList(const AtomicString& media);
 
     RefPtrWillBeMember<MediaQueryList> m_mediaQueryList;
     RefPtrWillBeMember<Listener> m_listener;
 };
 
 } // namespace blink
 
 #endif // HTMLSourceElement_h