<!DOCTYPE HTML>
<html>
<head>
<title>Iframe 1 for Bug 1640766</title>
</head>
<body>
<div>Iframe 1</div>
<script type="application/javascript">
if (parent == window) {
  let iframe = document.createElement("iframe");
  iframe.src = "http://example.org/tests/dom/base/test/iframe2_bug1640766.html";
  document.body.appendChild(iframe);
} else {
  window.onload = function() {
    top.opener.postMessage("ready", "*");
  };
}
</script>
</body>
</html>
