Remove isSupportedAttribute in svg

Source/core/svg/SVGPolyElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 24 matching lines @@
 }
 
 DEFINE_TRACE(SVGPolyElement)
 {
     visitor->trace(m_points);
     SVGGeometryElement::trace(visitor);
 }
 
 void SVGPolyElement::svgAttributeChanged(const QualifiedName& attrName)
 {
-    if (attrName != SVGNames::pointsAttr) {
-        SVGGeometryElement::svgAttributeChanged(attrName);
+    if (attrName == SVGNames::pointsAttr) {
+        SVGElement::InvalidationGuard invalidationGuard(this);
+
+        LayoutSVGShape* renderer = toLayoutSVGShape(this->layoutObject());
+        if (!renderer)
+            return;
+
+        renderer->setNeedsShapeUpdate();
+        markForLayoutAndParentResourceInvalidation(renderer);
         return;
     }
 
-    SVGElement::InvalidationGuard invalidationGuard(this);
-
-    LayoutSVGShape* renderer = toLayoutSVGShape(this->layoutObject());
-    if (!renderer)
-        return;
-
-    renderer->setNeedsShapeUpdate();
-    markForLayoutAndParentResourceInvalidation(renderer);
+    SVGGeometryElement::svgAttributeChanged(attrName);
 }
 
 }