Codebase Browser
chromium
Go to App

chromium/third_party/blink/web_tests/http/tests/serviceworker/fetch-error-messages.html 

<!DOCTYPE html>
<title>Service Worker: Error messages for fetch()</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/test-helpers.js"></script>
<script>

service_worker_test(
    'resources/fetch-error-messages-worker.js',
    'Error messages for fetch()');

</script>