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 eb689f8d31de6aa8ac41236735bd40703833aaf0..1789bd231deb978814551637da30ec0516615370 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/SVGGeometryElement.h"
 
 namespace WebCore {
 
-class SVGCircleElement FINAL : public SVGGeometryElement,
-                               public SVGExternalResourcesRequired {
+class SVGCircleElement FINAL : public SVGGeometryElement {
 public:
     static PassRefPtr<SVGCircleElement> create(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
 };