chromium/third_party/blink/web_tests/paint/invalidation/svg/mask-child-changes.svg

<svg width="800" height="600" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" onload="runRepaintAndPixelTest()">
<script xlink:href="../resources/text-based-repaint.js"/>
<mask id="Mask" maskUnits="userSpaceOnUse" x="0" y="0" width="800" height="300">
    <rect x="0" y="0" width="800" height="300" fill="none"/>
</mask>

<script>
function repaintTest() {
    document.getElementById("Mask").firstChild.nextSibling.setAttribute("fill", "red");
}
</script>

<rect x="0" y="100" width="800" height="100" fill="blue" mask="url(#Mask)"/>

</svg>