sandbox-self.html | Explore in Territory

<!DOCTYPE html>
<title>Return fullscreen permissions policy state from self and a sandboxed child frame</title>
<script>
  "use strict";
  window.onload = () => {
    let frame = document.createElement('iframe');
    frame.src = "/permissions-policy/resources/nested-sandbox.html";
    frame.sandbox = "allow-scripts";

    var handle_message = evt => {
      if (evt.source === frame.contentWindow) {
        window.parent.postMessage({
          "child": document.featurePolicy.allowedFeatures().includes("fullscreen"),
          "grandchild": evt.data
        },"*");
        document.body.removeChild(frame);
        window.removeEventListener('message', handle_message);
      }
    };
    window.addEventListener('message', handle_message);
    document.body.appendChild(frame);
  };
</script>

chromium/third_party/blink/web_tests/external/wpt/permissions-policy/resources/sandbox-self.html