[SVG] SVGLength{,List} migration to new SVG property impl.

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 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/svg/properties/NewSVGAnimatedProperty.h"
 
 #include "core/svg/SVGElement.h"
 
 namespace WebCore {
 
+NewSVGAnimatedPropertyBase::NewSVGAnimatedPropertyBase(SVGElement* contextElement, const QualifiedName& attributeName)
+    : m_contextElement(contextElement)
+    , m_attributeName(attributeName)
+{
+    contextElement->setContextElement();
+}
+
 NewSVGAnimatedPropertyBase::~NewSVGAnimatedPropertyBase()
 {
 }
 
 void NewSVGAnimatedPropertyBase::synchronizeAttribute()
 {
+    ASSERT(needsSynchronizeAttribute());
     AtomicString value(currentValueBase()->valueAsString());
     m_contextElement->setSynchronizedLazyAttribute(m_attributeName, value);
 }
 
 } // namespace WebCore