Make manual isSVG*Element() helpers as efficient as the generated ones

Source/core/svg/SVGGraphicsElement.h

Index: Source/core/svg/SVGGraphicsElement.h
diff --git a/Source/core/svg/SVGGraphicsElement.h b/Source/core/svg/SVGGraphicsElement.h
index 4b3f4222893b507eb3429ec0fb13d437aaf2929b..2862402cdd73825ecd7a5493a68f867a1f18f013 100644
--- a/Source/core/svg/SVGGraphicsElement.h
+++ b/Source/core/svg/SVGGraphicsElement.h
@@ -86,12 +86,12 @@ private:
     OwnPtr<AffineTransform> m_supplementalTransform;
 };
 
-inline bool isSVGGraphicsElement(const Node& node)
+inline bool isSVGGraphicsElement(const SVGElement& element)
 {
-    return node.isSVGElement() && toSVGElement(node).isSVGGraphicsElement();
+    return element.isSVGGraphicsElement();
 }
 
-DEFINE_ELEMENT_TYPE_CASTS_WITH_FUNCTION(SVGGraphicsElement);
+DEFINE_SVGELEMENT_TYPE_CASTS_WITH_FUNCTION(SVGGraphicsElement);
 
 } // namespace blink