<!DOCTYPE HTML>
<html>
<head>
  <meta http-equiv="content-type" content="text/html; charset=utf-8">
  <title>Test page for always sending a message to its opener through postMessage</title>
</head>
<body>
  <script>
  window.onload = () => {
    // The target origin is coming from the query string.
    let targetOrigin = window.location.search.substring(1);
    window.opener.postMessage("Message", targetOrigin);
  };
  </script>
</body>
</html>
