chromium/chrome/test/data/extensions/platform_apps/web_view/shim/guest.html

<!doctype html>
<!--
Copyright 2013 The Chromium Authors
Use of this source code is governed by a BSD-style license that can be
found in the LICENSE file.
-->
<html>
<head>
  <title>A guest that opens a new window.</title>
  <script type="text/javascript">
    window.newWindow = null;
    window.onload = () => {
      window.newWindow = window.open('empty_guest.html', 'namedWebview');
    };
  </script>
</head>
<body style="padding: 0; margin: 0;">
</body>
</html>