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

Source/core/html/HTMLOptGroupElement.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2010 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 20 matching lines @@
 namespace blink {
 
 class HTMLSelectElement;
 class HTMLDivElement;
 
 class CORE_EXPORT HTMLOptGroupElement final : public HTMLElement {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PassRefPtrWillBeRawPtr<HTMLOptGroupElement> create(Document&);
 
-    virtual bool isDisabledFormControl() const override;
+    bool isDisabledFormControl() const override;
     HTMLSelectElement* ownerSelectElement() const;
 
     String groupLabelText() const;
     HTMLDivElement& optGroupLabelElement() const;
 
 private:
     explicit HTMLOptGroupElement(Document&);
 
-    virtual bool supportsFocus() const override;
-    virtual void parseAttribute(const QualifiedName&, const AtomicString&) override;
-    virtual void childrenChanged(const ChildrenChange&) override;
-    virtual void accessKeyAction(bool sendMouseEvents) override;
-    virtual void didAddUserAgentShadowRoot(ShadowRoot&) override;
-    virtual void attach(const AttachContext& = AttachContext()) override;
-    virtual void detach(const AttachContext& = AttachContext()) override;
+    bool supportsFocus() const override;
+    void parseAttribute(const QualifiedName&, const AtomicString&) override;
+    void childrenChanged(const ChildrenChange&) override;
+    void accessKeyAction(bool sendMouseEvents) override;
+    void didAddUserAgentShadowRoot(ShadowRoot&) override;
+    void attach(const AttachContext& = AttachContext()) override;
+    void detach(const AttachContext& = AttachContext()) override;
 
     // <optgroup> might not have a layoutObject so we manually manage a cached style.
     void updateNonComputedStyle();
-    virtual ComputedStyle* nonLayoutObjectComputedStyle() const override;
-    virtual PassRefPtr<ComputedStyle> customStyleForLayoutObject() override;
+    ComputedStyle* nonLayoutObjectComputedStyle() const override;
+    PassRefPtr<ComputedStyle> customStyleForLayoutObject() override;
 
     void updateGroupLabel();
     void recalcSelectOptions();
 
     RefPtr<ComputedStyle> m_style;
 };
 
 } // namespace blink
 
 #endif // HTMLOptGroupElement_h