| <!DOCTYPE html> |
| <meta charset="utf-8"> |
| <iframe id="id_0"></iframe> |
| <script> |
| window.addEventListener("load", () => { |
| const iframe = document.getElementById("id_0") |
| // Discards the previous document |
| document.documentElement.appendChild(iframe) |
| const xhr = new XMLHttpRequest() |
| // LockManager is created after discarding |
| // At this point the new document is not there yet |
| iframe.contentWindow.navigator.locks.request("weblock_0", () => { |
| xhr.open("GET", "FOOBAR", false) |
| xhr.send() |
| // Now there is a new document |
| }) |
| }) |
| </script> |
