Codebase Browser
chromium
Go to App

chromium/third_party/blink/web_tests/external/wpt/content-security-policy/navigation/support/test_csp_self_window.sub.html 

<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<span id="escape">{{GET[window_url]}}</span>

<script>
  var window_url = document.getElementById("escape").textContent;
  window.open(window_url, "_self");
</script>