Remove support for the externalResourcesRequired attribute.

Source/core/svg/SVGElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) 2009 Cameron McCormack <cam@mcc.id.au>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 1079 matching lines @@
         animatableAttributes.add(SVGNames::clipPathUnitsAttr);
         animatableAttributes.add(SVGNames::cxAttr);
         animatableAttributes.add(SVGNames::cyAttr);
         animatableAttributes.add(SVGNames::diffuseConstantAttr);
         animatableAttributes.add(SVGNames::divisorAttr);
         animatableAttributes.add(SVGNames::dxAttr);
         animatableAttributes.add(SVGNames::dyAttr);
         animatableAttributes.add(SVGNames::edgeModeAttr);
         animatableAttributes.add(SVGNames::elevationAttr);
         animatableAttributes.add(SVGNames::exponentAttr);
-        animatableAttributes.add(SVGNames::externalResourcesRequiredAttr);
         animatableAttributes.add(SVGNames::filterResAttr);
         animatableAttributes.add(SVGNames::filterUnitsAttr);
         animatableAttributes.add(SVGNames::fxAttr);
         animatableAttributes.add(SVGNames::fyAttr);
         animatableAttributes.add(SVGNames::gradientTransformAttr);
         animatableAttributes.add(SVGNames::gradientUnitsAttr);
         animatableAttributes.add(SVGNames::heightAttr);
         animatableAttributes.add(SVGNames::in2Attr);
         animatableAttributes.add(SVGNames::inAttr);
         animatableAttributes.add(SVGNames::interceptAttr);
@@ skipping 67 matching lines @@
     }
 
     if (name == classAttr)
         return true;
 
     return animatableAttributes.contains(name);
 }
 #endif
 
 }