void SVGDocumentExtensions::addElementReferencingTarget(SVGElement* referencingElement, SVGElement* referencedElement)
{
    ASSERT(referencingElement);
    ASSERT(referencedElement);

    if (SVGElementSet* elements = m_elementDependencies.get(referencedElement)) {
        elements->add(referencingElement);
        return;
    }

    OwnPtrWillBeRawPtr<SVGElementSet> elements = adoptPtrWillBeNoop(new SVGElementSet);
    elements->add(referencingElement);
    m_elementDependencies.set(referencedElement, elements.release());
}