Update CSS classes to use OVERRIDE / FINAL when needed

Source/core/css/CSSViewportRule.h

Index: Source/core/css/CSSViewportRule.h
diff --git a/Source/core/css/CSSViewportRule.h b/Source/core/css/CSSViewportRule.h
index 2ef8c81511fa1d9f2ba61aac384dc687e0aaa8c9..50cd88a7eeda94e616c2ea26fa9d3fd7babde704 100644
--- a/Source/core/css/CSSViewportRule.h
+++ b/Source/core/css/CSSViewportRule.h
@@ -39,13 +39,13 @@ class CSSStyleDeclaration;
 class StyleRuleViewport;
 class StyleRuleCSSStyleDeclaration;
 
-class CSSViewportRule: public CSSRule {
+class CSSViewportRule FINAL: public CSSRule {
 public:
     static PassRefPtr<CSSViewportRule> create(StyleRuleViewport* viewportRule, CSSStyleSheet* sheet)
     {
         return adoptRef(new CSSViewportRule(viewportRule, sheet));
     }
-    ~CSSViewportRule();
+    virtual ~CSSViewportRule();
 
     virtual CSSRule::Type type() const OVERRIDE { return VIEWPORT_RULE; }
     virtual String cssText() const OVERRIDE;