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

Source/core/html/ClassList.h

 /*
  * Copyright (C) 2010 Google 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 28 matching lines @@
 typedef int ExceptionCode;
 
 class ClassList final : public DOMTokenList {
 public:
     static PassOwnPtrWillBeRawPtr<ClassList> create(Element* element)
     {
         return adoptPtrWillBeNoop(new ClassList(element));
     }
 
 #if !ENABLE(OILPAN)
-    virtual void ref() override;
-    virtual void deref() override;
+    void ref() override;
+    void deref() override;
 #endif
 
-    virtual unsigned length() const override;
-    virtual const AtomicString item(unsigned index) const override;
+    unsigned length() const override;
+    const AtomicString item(unsigned index) const override;
 
-    virtual Element* element() override { return m_element; }
+    Element* element() override { return m_element; }
 
     void clearValueForQuirksMode() { m_classNamesForQuirksMode = nullptr; }
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit ClassList(Element*);
 
-    virtual bool containsInternal(const AtomicString&) const override;
+    bool containsInternal(const AtomicString&) const override;
 
     const SpaceSplitString& classNames() const;
 
-    virtual const AtomicString& value() const override { return m_element->getAttribute(HTMLNames::classAttr); }
-    virtual void setValue(const AtomicString& value) override { m_element->setAttribute(HTMLNames::classAttr, value); }
+    const AtomicString& value() const override { return m_element->getAttribute(HTMLNames::classAttr); }
+    void setValue(const AtomicString& value) override { m_element->setAttribute(HTMLNames::classAttr, value); }
 
     RawPtrWillBeMember<Element> m_element;
     mutable OwnPtr<SpaceSplitString> m_classNamesForQuirksMode;
 };
 
 } // namespace blink
 
 #endif // ClassList_h