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

Source/core/svg/SVGGradientElement.h

Index: Source/core/svg/SVGGradientElement.h
diff --git a/Source/core/svg/SVGGradientElement.h b/Source/core/svg/SVGGradientElement.h
index f709bf0a931658c9d47654ede09469f3cb6bf812..b77dbaafcb170e963a03212f04d2b36d80874a9d 100644
--- a/Source/core/svg/SVGGradientElement.h
+++ b/Source/core/svg/SVGGradientElement.h
@@ -56,12 +56,12 @@ public:
 protected:
     SVGGradientElement(const QualifiedName&, Document&);
 
-    virtual void svgAttributeChanged(const QualifiedName&) override;
+    void svgAttributeChanged(const QualifiedName&) override;
 
 private:
-    virtual bool needsPendingResourceHandling() const override final { return false; }
+    bool needsPendingResourceHandling() const final { return false; }
 
-    virtual void childrenChanged(const ChildrenChange&) override final;
+    void childrenChanged(const ChildrenChange&) final;
 
     RefPtrWillBeMember<SVGAnimatedTransformList> m_gradientTransform;
     RefPtrWillBeMember<SVGAnimatedEnumeration<SVGSpreadMethodType>> m_spreadMethod;