<!DOCTYPE html>
<meta charset=utf-8>
<title>
  Check sandbox-flags inheritance in case of javascript window reuse.
</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
<script>
promise_test(async test => {
  let message = new Promise(resolve =>
    window.addEventListener("message", event => resolve(event.data))
  );

  // Create an initial empty document in the iframe, sandboxed. It will attempt
  // to load a slow page, but won't have ti