SVG: Items inserted into list should be made a tear-off.

Source/core/svg/properties/SVGPropertyTearOff.h

 /*
  * 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 65 matching lines @@
     SVGElement* contextElement()
     {
         return m_contextElement;
     }
 
     const QualifiedName& attributeName()
     {
         return m_attributeName;
     }
 
+    void attachToSVGElementAttribute(SVGElement* contextElement, const QualifiedName& attributeName)
+    {
+        ASSERT(!isImmutable());
+        ASSERT(contextElement);
+        ASSERT(attributeName != nullQName());
+        m_contextElement = contextElement;
+        m_attributeName = attributeName;
+    }
+
     virtual AnimatedPropertyType type() const = 0;
 
 protected:
     SVGPropertyTearOffBase(SVGElement* contextElement, PropertyIsAnimValType propertyIsAnimVal, const QualifiedName& attributeName = nullQName())
         : m_contextElement(contextElement)
         , m_propertyIsAnimVal(propertyIsAnimVal)
         , m_isReadOnlyProperty(false)
         , m_attributeName(attributeName)
     {
     }
@@ skipping 33 matching lines @@
         ASSERT(m_target);
     }
 
 private:
     RefPtr<Property> m_target;
 };
 
 }
 
 #endif // SVGPropertyTearOff_h