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

Source/core/css/CSSPageRule.h

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2006, 2008, 2012 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 22 matching lines @@
 class StyleRuleCSSStyleDeclaration;
 
 class CSSPageRule final : public CSSRule {
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PassRefPtrWillBeRawPtr<CSSPageRule> create(StyleRulePage* rule, CSSStyleSheet* sheet)
     {
         return adoptRefWillBeNoop(new CSSPageRule(rule, sheet));
     }
 
-    virtual ~CSSPageRule();
+    ~CSSPageRule() override;
 
-    virtual String cssText() const override;
-    virtual void reattach(StyleRuleBase*) override;
+    String cssText() const override;
+    void reattach(StyleRuleBase*) override;
 
     CSSStyleDeclaration* style() const;
 
     String selectorText() const;
     void setSelectorText(const String&);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     CSSPageRule(StyleRulePage*, CSSStyleSheet*);
 
-    virtual CSSRule::Type type() const override { return PAGE_RULE; }
+    CSSRule::Type type() const override { return PAGE_RULE; }
 
     RefPtrWillBeMember<StyleRulePage> m_pageRule;
     mutable RefPtrWillBeMember<StyleRuleCSSStyleDeclaration> m_propertiesCSSOMWrapper;
 };
 
 DEFINE_CSS_RULE_TYPE_CASTS(CSSPageRule, PAGE_RULE);
 
 } // namespace blink
 
 #endif // CSSPageRule_h