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

Source/core/css/CSSSupportsRule.h

Index: Source/core/css/CSSSupportsRule.h
diff --git a/Source/core/css/CSSSupportsRule.h b/Source/core/css/CSSSupportsRule.h
index e328b68637f58c9bd067d4bac1c140653a2bd4c6..2f395366d58ef717980901aed2d2abf44f8fa849 100644
--- a/Source/core/css/CSSSupportsRule.h
+++ b/Source/core/css/CSSSupportsRule.h
@@ -43,9 +43,9 @@ public:
         return adoptRefWillBeNoop(new CSSSupportsRule(rule, sheet));
     }
 
-    virtual ~CSSSupportsRule() { }
+    ~CSSSupportsRule() override { }
 
-    virtual String cssText() const override;
+    String cssText() const override;
 
     String conditionText() const;
 
@@ -54,7 +54,7 @@ public:
 private:
     CSSSupportsRule(StyleRuleSupports*, CSSStyleSheet*);
 
-    virtual CSSRule::Type type() const override { return SUPPORTS_RULE; }
+    CSSRule::Type type() const override { return SUPPORTS_RULE; }
 };
 
 DEFINE_CSS_RULE_TYPE_CASTS(CSSSupportsRule, SUPPORTS_RULE);