Figure out if we need to support dummy gradients still

QList<QQuickGradient *> DeclarativeTheme3D::gradientList()
{
    QList<QQuickGradient *> list;
    if (m_gradients.isEmpty()) {
        // Create QQuickGradients from theme's gradients
        m_dummyGradients = true;
        for (QLinearGradient &gradient : Q3DTheme::baseGradients())
            list.append(convertGradient(gradient));
    } else {
        list = m_gradients;
    }    return list;
}