bool RenderSVGTransformableContainer::calculateLocalTransform()
{
    SVGGraphicsElement* element = toSVGGraphicsElement(node());

    // If we're either the renderer for a <use> element, or for any <g> element inside the shadow
    // tree, that was created during the use/symbol/svg expansion in SVGUseElement. These containers
    // need to respect the translations induced by their corresponding use elements x/y attributes.
    SVGUseElement* useElement = 0;
    if (element->hasTagName(SVGNames::useTag))
        useElement = toSVGUseElement(element);
    else if (element->isInShadowTree() && element->hasTagName(SVGNames::gTag)) {
        SVGElement* correspondingElement = element->correspondingElement();
        if (correspondingElement && correspondingElement->hasTagName(SVGNames::useTag))
            useElement = toSVGUseElement(correspondingElement);
    }

    if (useElement) {
        SVGLengthContext lengthContext(useElement);
        FloatSize translation(useElement->x().value(lengthContext), useElement->y().value(lengthContext));
        if (translation != m_lastTranslation)
            m_needsTransformUpdate = true;
        m_lastTranslation = translation;
    }

    m_didTransformToRootUpdate = m_needsTransformUpdate || SVGRenderSupport::transformToRootChanged(parent());
    if (!m_needsTransformUpdate)
        return false;

    m_localTransform = element->animatedLocalTransform();
    m_localTransform.translate(m_lastTranslation.width(), m_lastTranslation.height());
    m_needsTransformUpdate = false;
    return true;
}