chromium/third_party/blink/web_tests/external/wpt/workers/non-automated/infinite-sibling.html

<!doctype html>
<title>infinite sibling workers</title>
<p>The number below should be increasing (ideally never-ending).</p>
<div>0</div>
<script>
var worker = new Worker('infinite-sibling.js');
var div = document.getElementsByTagName('div')[0];
var i = 0;
worker.onmessage = function(e) {
  div.textContent = i + e.data;
}
</script>