Intermittent PASS in /preload/preload-error.sub.html #37177

 Stable unexpected results (1): 
  ▶ OK /preload/preload-error.sub.html
  │   ▶ PASS [expected FAIL] success (style): main
  │   │ PASS [expected FAIL] 404 (style): main
  │   └ PASS [expected FAIL] success (xhr): main
  │   ▶ FAIL [expected PASS] CORS (script): main
  │   │   → assert_greater_than: http://not-web-platform.test:8000/preload/resources/dummy.js?pipe=header%28Access-Control-Allow-Origin%2C*%29&label=script should be loaded expected a number greater than 0 but got 0
  │   │ FAIL [expected PASS] MIME-error (script): main
  │   │   → assert_greater_than: http://web-platform.test:8000/preload/resources/dummy.css?pipe=header%28Content-Type%2Ctext%2Fnotjavascript%29&label=script should be loaded expected a number greater than 0 but got 0
  │   │ 
  │   │ verifyLoadedAndNoDoubleDownload@http://web-platform.test:8000/preload/resources/preload_helper.js:45:24
  │   │ runTest/<@http://web-platform.test:8000/preload/preload-error.sub.html:126:36
  │   │ async*Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:2684:25
  │   │ promise_test/tests.promise_tests</<@http://web-platform.test:8000/resources/testharness.js:738:36
  └   └ promise_test/tests.promise_tests<@http://web-platform.test:8000/resources/testharness.js:737:20