Remove support for the externalResourcesRequired attribute.

Source/core/svg/SVGFilterElement.cpp

Index: Source/core/svg/SVGFilterElement.cpp
diff --git a/Source/core/svg/SVGFilterElement.cpp b/Source/core/svg/SVGFilterElement.cpp
index 391a1d88b1987b25374ad06ee8427acdebe3b498..beb494d8bff4560ae6a86ab10d442a67faf1dd52 100644
--- a/Source/core/svg/SVGFilterElement.cpp
+++ b/Source/core/svg/SVGFilterElement.cpp
@@ -43,7 +43,6 @@ DEFINE_ANIMATED_LENGTH(SVGFilterElement, SVGNames::heightAttr, Height, height)
 DEFINE_ANIMATED_INTEGER_MULTIPLE_WRAPPERS(SVGFilterElement, SVGNames::filterResAttr, filterResXIdentifier(), FilterResX, filterResX)
 DEFINE_ANIMATED_INTEGER_MULTIPLE_WRAPPERS(SVGFilterElement, SVGNames::filterResAttr, filterResYIdentifier(), FilterResY, filterResY)
 DEFINE_ANIMATED_STRING(SVGFilterElement, XLinkNames::hrefAttr, Href, href)
-DEFINE_ANIMATED_BOOLEAN(SVGFilterElement, SVGNames::externalResourcesRequiredAttr, ExternalResourcesRequired, externalResourcesRequired)
 
 BEGIN_REGISTER_ANIMATED_PROPERTIES(SVGFilterElement)
     REGISTER_LOCAL_ANIMATED_PROPERTY(filterUnits)
@@ -55,7 +54,6 @@ BEGIN_REGISTER_ANIMATED_PROPERTIES(SVGFilterElement)
     REGISTER_LOCAL_ANIMATED_PROPERTY(filterResX)
     REGISTER_LOCAL_ANIMATED_PROPERTY(filterResY)
     REGISTER_LOCAL_ANIMATED_PROPERTY(href)
-    REGISTER_LOCAL_ANIMATED_PROPERTY(externalResourcesRequired)
 END_REGISTER_ANIMATED_PROPERTIES
 
 inline SVGFilterElement::SVGFilterElement(const QualifiedName& tagName, Document& document)
@@ -105,7 +103,6 @@ bool SVGFilterElement::isSupportedAttribute(const QualifiedName& attrName)
     DEFINE_STATIC_LOCAL(HashSet<QualifiedName>, supportedAttributes, ());
     if (supportedAttributes.isEmpty()) {
         SVGURIReference::addSupportedAttributes(supportedAttributes);
-        SVGExternalResourcesRequired::addSupportedAttributes(supportedAttributes);
         supportedAttributes.add(SVGNames::filterUnitsAttr);
         supportedAttributes.add(SVGNames::primitiveUnitsAttr);
         supportedAttributes.add(SVGNames::xAttr);
@@ -145,8 +142,7 @@ void SVGFilterElement::parseAttribute(const QualifiedName& name, const AtomicStr
             setFilterResXBaseValue(x);
             setFilterResYBaseValue(y);
         }
-    } else if (SVGURIReference::parseAttribute(name, value)
-             || SVGExternalResourcesRequired::parseAttribute(name, value)) {
+    } else if (SVGURIReference::parseAttribute(name, value)) {
     } else
         ASSERT_NOT_REACHED();