Remove support for the externalResourcesRequired attribute.

Source/core/svg/SVGCircleElement.h

Index: Source/core/svg/SVGCircleElement.h
diff --git a/Source/core/svg/SVGCircleElement.h b/Source/core/svg/SVGCircleElement.h
index f720aa64809b42aa4a112324ec24b6a167fccf4d..2dc468a38c748ff943185e8328c6bd5f8d6609b3 100644
--- a/Source/core/svg/SVGCircleElement.h
+++ b/Source/core/svg/SVGCircleElement.h
@@ -24,13 +24,11 @@
 #include "SVGNames.h"
 #include "core/svg/SVGAnimatedBoolean.h"
 #include "core/svg/SVGAnimatedLength.h"
-#include "core/svg/SVGExternalResourcesRequired.h"
 #include "core/svg/SVGGraphicsElement.h"
 
 namespace WebCore {
 
-class SVGCircleElement FINAL : public SVGGraphicsElement,
-                               public SVGExternalResourcesRequired {
+class SVGCircleElement FINAL : public SVGGraphicsElement {
 public:
     static PassRefPtr<SVGCircleElement> create(const QualifiedName&, Document&);
 
@@ -52,7 +50,6 @@ private:
         DECLARE_ANIMATED_LENGTH(Cx, cx)
         DECLARE_ANIMATED_LENGTH(Cy, cy)
         DECLARE_ANIMATED_LENGTH(R, r)
-        DECLARE_ANIMATED_BOOLEAN(ExternalResourcesRequired, externalResourcesRequired)
     END_DECLARE_ANIMATED_PROPERTIES
 };