<!DOCTYPE html>
<html class="reftest-wait">
<title>CSS Position Test: Chrome crash for ::backdrop transitioning overlay for popover</title>
<link rel="help" href="https://crbug.com/1446479">
<script src="/common/reftest-wait.js"></script>
<style>
  #popover {
    transition: overlay 60s step-end;
    display: block;
  }
  #popover::backdrop {
    background: rgba(0, 0, 0, 0.2);
  }
</style>
<p>PASS if no crash.</p>
<div id="popover" popover></div>
<script>
  requestAnimationFrame(() => {
    popover.showPopover();
    requestAnimationFrame(() => {
      popover.hidePopover();
      takeScreenshot();
    });
  });
</script>
