Use DEFINE_NODE_TYPE_CASTS instead of using manual toSVGFooElement()

Source/core/svg/SVGCircleElement.h

Index: Source/core/svg/SVGCircleElement.h
diff --git a/Source/core/svg/SVGCircleElement.h b/Source/core/svg/SVGCircleElement.h
index ae702f6974fc469467df2977627bb73f4e0b64ab..f720aa64809b42aa4a112324ec24b6a167fccf4d 100644
--- a/Source/core/svg/SVGCircleElement.h
+++ b/Source/core/svg/SVGCircleElement.h
@@ -56,11 +56,7 @@ private:
     END_DECLARE_ANIMATED_PROPERTIES
 };
 
-inline SVGCircleElement* toSVGCircleElement(Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(SVGNames::circleTag));
-    return static_cast<SVGCircleElement*>(node);
-}
+DEFINE_NODE_TYPE_CASTS(SVGCircleElement, hasTagName(SVGNames::circleTag));
 
 } // namespace WebCore