Intermittent failure in /html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-cross-origin.sub.window.html

```
  ▶ Unexpected subtest result in /html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-cross-origin.sub.window.html:
  └ PASS [expected FAIL] b'Cross-origin navigation started from unload handler must be ignored'
```