Fix virtual/override/final usage in Source/core/{animation,css,style}/.

Source/core/css/CSSKeyframeRule.h

 /*
  * Copyright (C) 2007, 2008, 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 21 matching lines @@
 namespace blink {
 
 class CSSKeyframesRule;
 class CSSStyleDeclaration;
 class ExceptionState;
 class KeyframeStyleRuleCSSStyleDeclaration;
 
 class CSSKeyframeRule final : public CSSRule {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    virtual ~CSSKeyframeRule();
+    ~CSSKeyframeRule() override;
 
-    virtual String cssText() const override { return m_keyframe->cssText(); }
-    virtual void reattach(StyleRuleBase*) override;
+    String cssText() const override { return m_keyframe->cssText(); }
+    void reattach(StyleRuleBase*) override;
 
     String keyText() const { return m_keyframe->keyText(); }
     void setKeyText(const String&, ExceptionState&);
 
     CSSStyleDeclaration* style() const;
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     CSSKeyframeRule(StyleRuleKeyframe*, CSSKeyframesRule* parent);
 
-    virtual CSSRule::Type type() const override { return KEYFRAME_RULE; }
+    CSSRule::Type type() const override { return KEYFRAME_RULE; }
 
     RefPtrWillBeMember<StyleRuleKeyframe> m_keyframe;
     mutable RefPtrWillBeMember<KeyframeStyleRuleCSSStyleDeclaration> m_propertiesCSSOMWrapper;
 
     friend class CSSKeyframesRule;
 };
 
 DEFINE_CSS_RULE_TYPE_CASTS(CSSKeyframeRule, KEYFRAME_RULE);
 
 } // namespace blink
 
 #endif // CSSKeyframeRule_h