Remove toSVGStopElement(SVGElement*) because it can be covered by toSVGStopElement(Node*)

Source/core/svg/SVGStopElement.h

Index: Source/core/svg/SVGStopElement.h
diff --git a/Source/core/svg/SVGStopElement.h b/Source/core/svg/SVGStopElement.h
index 025e57dc3acb98b5c6bb1afaff03602ceafe3286..a19d92830a01e9437b95aff07e220505e52c6ab0 100644
--- a/Source/core/svg/SVGStopElement.h
+++ b/Source/core/svg/SVGStopElement.h
@@ -21,7 +21,6 @@
 #ifndef SVGStopElement_h
 #define SVGStopElement_h
 
-#include "SVGNames.h"
 #include "core/svg/SVGAnimatedNumber.h"
 #include "core/svg/SVGElement.h"
 
@@ -50,12 +49,6 @@ private:
     END_DECLARE_ANIMATED_PROPERTIES
 };
 
-inline SVGStopElement* toSVGStopElement(Node* node)
-{
-    ASSERT_WITH_SECURITY_IMPLICATION(!node || node->hasTagName(SVGNames::stopTag));
-    return static_cast<SVGStopElement*>(node);
-}
-
 inline SVGStopElement* toSVGStopElement(SVGElement* element)
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!element || element->isGradientStop());