Remove support for the externalResourcesRequired attribute.

Source/core/svg/SVGPathElement.idl

 /*
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  * Copyright (C) 2006 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 87 matching lines @@
     SVGPathSegCurvetoQuadraticSmoothAbs createSVGPathSegCurvetoQuadraticSmoothAbs([Default=Undefined] optional float x,
                                                                                   [Default=Undefined] optional float y);
     SVGPathSegCurvetoQuadraticSmoothRel createSVGPathSegCurvetoQuadraticSmoothRel([Default=Undefined] optional float x,
                                                                                   [Default=Undefined] optional float y);
 
     readonly attribute SVGPathSegList pathSegList;
     readonly attribute SVGPathSegList normalizedPathSegList;
     readonly attribute SVGPathSegList animatedPathSegList;
     readonly attribute SVGPathSegList animatedNormalizedPathSegList;
 };
-
-SVGPathElement implements SVGExternalResourcesRequired;