chromium/third_party/blink/web_tests/http/tests/fetch/referrer/resources/origin-when-cross-origin-simple-onfetch-js.php

<?php
  header('Cache-control: no-store');
  header('Content-Security-Policy: referrer origin-when-cross-origin');
  header('Content-Type: application/javascript');
?>

self.addEventListener('fetch', e => e.respondWith(fetch(e.request)));