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 2b8f6172bff3ba166e679eddc1a619c37b268ad0..67758431ec254527e6d579aa7a7f3f13e5f9e61b 100644
--- a/Source/core/svg/SVGGradientElement.cpp
+++ b/Source/core/svg/SVGGradientElement.cpp
@@ -42,14 +42,12 @@ 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
 
@@ -67,7 +65,6 @@ 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);
@@ -106,8 +103,6 @@ void SVGGradientElement::parseAttribute(const QualifiedName& name, const AtomicS
 
     if (SVGURIReference::parseAttribute(name, value))
         return;
-    if (SVGExternalResourcesRequired::parseAttribute(name, value))
-        return;
 
     ASSERT_NOT_REACHED();
 }