chromium/third_party/blink/web_tests/external/wpt/css/filter-effects/svg-mutation-drop-shadow-offset.html

<!doctype html>
<html class="reftest-wait">
<title>Filter Effects: changing offset of drop-shadow() function on an SVG element</title>
<link rel="help" href="https://drafts.fxtf.org/filter-effects-1/#FilterProperty">
<link rel="help" href="https://drafts.fxtf.org/filter-effects-1/#funcdef-filter-drop-shadow">
<link rel="match" href="reference/green-100x100.html">
<script src="/common/rendering-utils.js"></script>
<script src="/common/reftest-wait.js"></script>
<svg>
  <rect width="100" height="100" fill="red"/>
  <rect id="target" width="50" height="100" fill="green" filter="drop-shadow(5px 0 green)"/>
</svg>
<script>
  waitForAtLeastOneFrame().then(() => {
    let rect = document.getElementById("target");
    rect.setAttribute("filter", "drop-shadow(50px 0 green)");
    takeScreenshot();
  });
</script>