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

Source/core/html/track/AudioTrackList.h

Index: Source/core/html/track/AudioTrackList.h
diff --git a/Source/core/html/track/AudioTrackList.h b/Source/core/html/track/AudioTrackList.h
index 5b2be32d72c712cd4f258006b3eb13af9016c9b0..cc220c9a6e45ee35cddb769979e5983a90a68f10 100644
--- a/Source/core/html/track/AudioTrackList.h
+++ b/Source/core/html/track/AudioTrackList.h
@@ -15,12 +15,12 @@ class AudioTrackList final : public TrackListBase<AudioTrack> {
 public:
     static PassRefPtrWillBeRawPtr<AudioTrackList> create(HTMLMediaElement&);
 
-    virtual ~AudioTrackList();
+    ~AudioTrackList() override;
 
     bool hasEnabledTrack() const;
 
     // EventTarget
-    virtual const AtomicString& interfaceName() const override;
+    const AtomicString& interfaceName() const override;
 
 private:
     explicit AudioTrackList(HTMLMediaElement&);