Remove support for the externalResourcesRequired attribute.

Source/core/svg/SVGGradientElement.cpp

Index: Source/core/svg/SVGGradientElement.cpp
diff --git a/Source/core/svg/SVGGradientElement.cpp b/Source/core/svg/SVGGradientElement.cpp
index a9a85d2e449746b8859e4ef565b6e505089cbfc6..0ae0c047406a8528b1d0821447782fc5c366cd18 100644
--- a/Source/core/svg/SVGGradientElement.cpp
+++ b/Source/core/svg/SVGGradientElement.cpp
@@ -40,14 +40,12 @@ DEFINE_ANIMATED_ENUMERATION(SVGGradientElement, SVGNames::spreadMethodAttr, Spre
 DEFINE_ANIMATED_ENUMERATION(SVGGradientElement, SVGNames::gradientUnitsAttr, GradientUnits, gradientUnits, SVGUnitTypes::SVGUnitType)
 DEFINE_ANIMATED_TRANSFORM_LIST(SVGGradientElement, SVGNames::gradientTransformAttr, GradientTransform, gradientTransform)
 DEFINE_ANIMATED_STRING(SVGGradientElement, XLinkNames::hrefAttr, Href, href)
-DEFINE_ANIMATED_BOOLEAN(SVGGradientElement, SVGNames::externalResourcesRequiredAttr, ExternalResourcesRequired, externalResourcesRequired)
 
 BEGIN_REGISTER_ANIMATED_PROPERTIES(SVGGradientElement)
     REGISTER_LOCAL_ANIMATED_PROPERTY(spreadMethod)
     REGISTER_LOCAL_ANIMATED_PROPERTY(gradientUnits)
     REGISTER_LOCAL_ANIMATED_PROPERTY(gradientTransform)
     REGISTER_LOCAL_ANIMATED_PROPERTY(href)
-    REGISTER_LOCAL_ANIMATED_PROPERTY(externalResourcesRequired)
     REGISTER_PARENT_ANIMATED_PROPERTIES(SVGElement)
 END_REGISTER_ANIMATED_PROPERTIES
 
@@ -65,7 +63,6 @@ bool SVGGradientElement::isSupportedAttribute(const QualifiedName& attrName)
     DEFINE_STATIC_LOCAL(HashSet<QualifiedName>, supportedAttributes, ());
     if (supportedAttributes.isEmpty()) {
         SVGURIReference::addSupportedAttributes(supportedAttributes);
-        SVGExternalResourcesRequired::addSupportedAttributes(supportedAttributes);
         supportedAttributes.add(SVGNames::gradientUnitsAttr);
         supportedAttributes.add(SVGNames::gradientTransformAttr);
         supportedAttributes.add(SVGNames::spreadMethodAttr);
@@ -104,8 +101,6 @@ void SVGGradientElement::parseAttribute(const QualifiedName& name, const AtomicS
 
     if (SVGURIReference::parseAttribute(name, value))
         return;
-    if (SVGExternalResourcesRequired::parseAttribute(name, value))
-        return;
 
     ASSERT_NOT_REACHED();
 }