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

Source/core/html/track/vtt/VTTElement.h

Index: Source/core/html/track/vtt/VTTElement.h
diff --git a/Source/core/html/track/vtt/VTTElement.h b/Source/core/html/track/vtt/VTTElement.h
index 20b522804a45256a98b6269c3b662afaa4e6cc6c..d8ecd086a07317478908f4241b851f099057d795 100644
--- a/Source/core/html/track/vtt/VTTElement.h
+++ b/Source/core/html/track/vtt/VTTElement.h
@@ -48,7 +48,7 @@ public:
     static PassRefPtrWillBeRawPtr<VTTElement> create(const QualifiedName&, Document*);
     PassRefPtrWillBeRawPtr<HTMLElement> createEquivalentHTMLElement(Document&);
 
-    virtual PassRefPtrWillBeRawPtr<Element> cloneElementWithoutAttributesAndChildren() override;
+    PassRefPtrWillBeRawPtr<Element> cloneElementWithoutAttributesAndChildren() override;
 
     void setVTTNodeType(VTTNodeType type) { m_webVTTNodeType = static_cast<unsigned>(type); }
     VTTNodeType webVTTNodeType() const { return static_cast<VTTNodeType>(m_webVTTNodeType); }
@@ -56,7 +56,7 @@ public:
     bool isPastNode() const { return m_isPastNode; }
     void setIsPastNode(bool);
 
-    virtual bool isVTTElement() const override { return true; }
+    bool isVTTElement() const override { return true; }
     AtomicString language() const { return m_language; }
     void setLanguage(AtomicString value) { m_language = value; }