load_img_and_post_result_header.html

<html>
<body>
  <script>
    var img = document.createElement("img");
    img.src = "/content-security-policy/support/pass.png";
    img.onload = function() { parent.postMessage('img loaded', '*'); }
    img.onerror = function() { parent.postMessage('img not loaded', '*'); }
    document.body.appendChild(img);
  </script>
</body>
</html>

chromium/third_party/blink/web_tests/external/wpt/content-security-policy/generic/support/load_img_and_post_result_header.html