chromium/third_party/blink/web_tests/fast/table/cell-percent-padding.html

<!DOCTYPE html>
<style>
th {
  overflow: scroll;
  column-count: 3;
  direction: rtl;
  padding-left: 100%;
  padding-right: 10px;
}
</style>
<script src='../../resources/testharness.js'></script>
<script src='../../resources/testharnessreport.js'></script>
<script>
async_test((t) => {
  document.addEventListener("DOMContentLoaded", () => {
    let th = document.createElement('th');
    document.body.appendChild(th);
    t.done();
  });
});
</script>