chromium/third_party/blink/web_tests/paint/invalidation/svg/path-pathlength-change.html

<!DOCTYPE html>
<script src="../resources/text-based-repaint.js"></script>
<script>
window.onload = runRepaintAndPixelTest;

function repaintTest() {
  document.querySelector('path').setAttribute('pathLength', 200);
}
</script>
<svg width="400" height="400">
  <path pathLength="0" d="M100,100h100v100h-100z" fill="none"
        stroke="blue" stroke-width="20" stroke-dasharray="25"/>
</svg>