<!DOCTYPE html>
<title>::backdrop for a fullscreen iframe element</title>
<script src="../trusted-click.js"></script>
<style>
iframe::backdrop {
  background: green;
}
</style>
<iframe></iframe>
<script>
testRunner.waitUntilDone();
// TODO: "var t" is silly everywhere in this dir
var t = { step_func: func => func() };
trusted_request(t, document.querySelector("iframe"));
document.addEventListener("fullscreenchange", function() {
  testRunner.notifyDone();
});
</script>