Remove isSupportedAttribute in svg

Source/core/svg/SVGFEDropShadowElement.cpp

Index: Source/core/svg/SVGFEDropShadowElement.cpp
diff --git a/Source/core/svg/SVGFEDropShadowElement.cpp b/Source/core/svg/SVGFEDropShadowElement.cpp
index 161de2d7c95de9ecf850efd706e5cad2030b887a..5a11efa7da16df238b3647f53b35dc79e0757905 100644
--- a/Source/core/svg/SVGFEDropShadowElement.cpp
+++ b/Source/core/svg/SVGFEDropShadowElement.cpp
@@ -60,36 +60,18 @@ void SVGFEDropShadowElement::setStdDeviation(float x, float y)
     invalidate();
 }
 
-bool SVGFEDropShadowElement::isSupportedAttribute(const QualifiedName& attrName)
-{
-    DEFINE_STATIC_LOCAL(HashSet<QualifiedName>, supportedAttributes, ());
-    if (supportedAttributes.isEmpty()) {
-        supportedAttributes.add(SVGNames::inAttr);
-        supportedAttributes.add(SVGNames::dxAttr);
-        supportedAttributes.add(SVGNames::dyAttr);
-        supportedAttributes.add(SVGNames::stdDeviationAttr);
-    }
-    return supportedAttributes.contains<SVGAttributeHashTranslator>(attrName);
-}
-
 void SVGFEDropShadowElement::svgAttributeChanged(const QualifiedName& attrName)
 {
-    if (!isSupportedAttribute(attrName)) {
-        SVGFilterPrimitiveStandardAttributes::svgAttributeChanged(attrName);
-        return;
-    }
-
-    SVGElement::InvalidationGuard invalidationGuard(this);
-
     if (attrName == SVGNames::inAttr
         || attrName == SVGNames::stdDeviationAttr
         || attrName == SVGNames::dxAttr
         || attrName == SVGNames::dyAttr) {
+        SVGElement::InvalidationGuard invalidationGuard(this);
         invalidate();
         return;
     }
 
-    ASSERT_NOT_REACHED();
+    SVGFilterPrimitiveStandardAttributes::svgAttributeChanged(attrName);
 }
 
 PassRefPtrWillBeRawPtr<FilterEffect> SVGFEDropShadowElement::build(SVGFilterBuilder* filterBuilder, Filter* filter)