textarea-custom-resizer.html | Explore in Territory

<!doctype HTML>
<style>
::-webkit-resizer {
    background: red;
}
</style>
<textarea id="target" style="width: 200px; height: 200px;"></textarea>
<script>
if (window.testRunner)
  testRunner.waitUntilDone();
onload = function() {
  requestAnimationFrame(function() {
    target.style.width = "400px";
    if (window.testRunner)
      testRunner.notifyDone();
  });
}
</script>

chromium/third_party/blink/web_tests/paint/invalidation/forms/textarea-custom-resizer.html