Allow determining if an SVG value has been specified

Source/core/svg/properties/NewSVGAnimatedProperty.cpp

 /*
  * Copyright (C) 2013 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 63 matching lines @@
     m_isAnimating = false;
 }
 
 void NewSVGAnimatedPropertyBase::synchronizeAttribute()
 {
     ASSERT(needsSynchronizeAttribute());
     AtomicString value(currentValueBase()->valueAsString());
     m_contextElement->setSynchronizedLazyAttribute(m_attributeName, value);
 }
 
+bool NewSVGAnimatedPropertyBase::isSpecified() const
+{
+    return isAnimating() || contextElement()->hasAttribute(attributeName());
+}
+
 void NewSVGAnimatedPropertyBase::commitChange()
 {
     contextElement()->invalidateSVGAttributes();
     contextElement()->svgAttributeChanged(m_attributeName);
 }
 
 } // namespace WebCore