Test run such as |./mach web-platform-tests _mozilla/service-workers/service-worker/shared-worker-controlled.https.html| Actual Result: Harness status: Error Error: Script file not found: resources/dummy-shared-worker.js Found 3 tests 1 Fail 2 Timeout Details: Fail Verify subresource loads in SharedWorker are controlled by a Service Worker assert_equals: expected "intercepted by service worker" but got "{\"error\": {\"message\": \"\", \"code\": 404}}" @https://web-platform.test:8443/_mozilla/service-workers/service-worker/shared-worker-controlled.https.html:26:11 Promise*@https://web-platform.test:8443/_mozilla/service-workers/service-worker/shared-worker-controlled.https.html:13:12 Test.prototype.step@https://web-platform.test:8443/resources/testharness.js:1371:20 promise_test/tests.promise_tests<@https://web-platform.test:8443/resources/testharness.js:527:36 Promise*promise_test/<@https://web-platform.test:8443/resources/testharness.js:523:39 Test.prototype.step@https://web-platform.test:8443/resources/testharness.js:1371:20 promise_test@https://web-platform.test:8443/resources/testharness.js:521:9 @https://web-platform.test:8443/_mozilla/service-workers/service-worker/shared-worker-controlled.https.html:8:1 Timeout Verify SharedWorker construction is controlled by a Service Worker -> timed out Timeout Verify importScripts from SharedWorker is controlled by a Service Worker -> timed out Traces: https://pastebin.mozilla.org/8838600

I believe workers and service workers should implement nsINetworkInterceptController themselves since they are "non-subresource" requests and should query the service worker registrations based on their URL even if the parent document is not controlled. https://fetch.spec.whatwg.org/#non-subresource-request

(Updating the title a bit based on https://etherpad.mozilla.org/blink-sw-tests)

All dependents fixed.