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

Source/core/html/track/TextTrackList.h

 /*
  * Copyright (C) 2011, 2012 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 30 matching lines @@
 class TextTrack;
 
 class TextTrackList final : public EventTargetWithInlineData, public RefCountedWillBeNoBase<TextTrackList> {
     DEFINE_WRAPPERTYPEINFO();
     REFCOUNTED_EVENT_TARGET(TextTrackList);
 public:
     static PassRefPtrWillBeRawPtr<TextTrackList> create(HTMLMediaElement* owner)
     {
         return adoptRefWillBeNoop(new TextTrackList(owner));
     }
-    virtual ~TextTrackList();
+    ~TextTrackList() override;
 
     unsigned length() const;
     int getTrackIndex(TextTrack*);
     int getTrackIndexRelativeToRenderedTracks(TextTrack*);
     bool contains(TextTrack*) const;
 
     TextTrack* item(unsigned index);
     TextTrack* getTrackById(const AtomicString& id);
     void append(PassRefPtrWillBeRawPtr<TextTrack>);
     void remove(TextTrack*);
 
     // EventTarget
-    virtual const AtomicString& interfaceName() const override;
-    virtual ExecutionContext* executionContext() const override;
+    const AtomicString& interfaceName() const override;
+    ExecutionContext* executionContext() const override;
 
     DEFINE_ATTRIBUTE_EVENT_LISTENER(addtrack);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(change);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(removetrack);
 
 #if !ENABLE(OILPAN)
     void clearOwner();
 #endif
     HTMLMediaElement* owner() const;
 
@@ skipping 17 matching lines @@
     OwnPtrWillBeMember<GenericEventQueue> m_asyncEventQueue;
 
     WillBeHeapVector<RefPtrWillBeMember<TextTrack>> m_addTrackTracks;
     WillBeHeapVector<RefPtrWillBeMember<TextTrack>> m_elementTracks;
     WillBeHeapVector<RefPtrWillBeMember<TextTrack>> m_inbandTracks;
 };
 
 } // namespace blink
 
 #endif // TextTrackList_h