ServiceWorker: Enable ServiceWorkerRegistration and update layout tests

LayoutTests/http/tests/serviceworker/resources/test-helpers.js

 // Adapter for testharness.js-style tests with Service Workers
 
 function service_worker_unregister_and_register(test, url, scope) {
     var options = scope ? { scope: scope } : {};
     return navigator.serviceWorker.unregister(scope).then(
         test.step_func(function() {
             return navigator.serviceWorker.register(url, options);
         }),
         unreached_rejection(test, 'Unregister should not fail')
     ).then(test.step_func(function(worker) {
@@ skipping 41 matching lines @@
     });
   iframe.src = '';
   iframe.remove();
   return saw_unload;
 }
 
 function normalizeURL(url) {
   return new URL(url, document.location).toString().replace(/#.*$/, '');
 }
 
+function wait_for_update(test, registration) {
+    return new Promise(test.step_func(function(resolve) {
+        registration.addEventListener('updatefound', test.step_func(function() {
+            resolve(registration.installing);
+        }));
+    }));
+}
+
 function wait_for_state(test, worker, state) {
-    return new Promise(test.step_func(function(resolve, reject) {
+    return new Promise(test.step_func(function(resolve) {
         worker.addEventListener('statechange', test.step_func(function() {
             if (worker.state === state)
                 resolve(state);
         }));
     }));
 }
 
 (function() {
   function fetch_tests_from_worker(worker) {
     return new Promise(function(resolve, reject) {
@@ skipping 31 matching lines @@
       }
     }
   };
 
   function service_worker_test(url, description) {
     var scope = window.location.origin + '/service-worker-scope/' +
       window.location.pathname;
 
     var test = async_test(description);
     service_worker_unregister_and_register(test, url, scope)
+      .then(function(registration) {
+          return wait_for_update(test, registration);
+        })
       .then(function(worker) { return fetch_tests_from_worker(worker); })
       .then(function() { return navigator.serviceWorker.unregister(scope); })
       .then(function() { test.done(); })
       .catch(test.step_func(function(e) { throw e; }));
   };
 
   self.service_worker_test = service_worker_test;
 })();
 
 function get_host_info() {
@@ skipping 15 matching lines @@
         HTTP_ORIGIN: 'http://' + ORIGINAL_HOST + ':' + HTTP_PORT,
         HTTPS_ORIGIN: 'https://' + ORIGINAL_HOST + ':' + HTTPS_PORT,
         HTTP_REMOTE_ORIGIN: 'http://' + REMOTE_HOST + ':' + HTTP_PORT,
         HTTPS_REMOTE_ORIGIN: 'https://' + REMOTE_HOST + ':' + HTTPS_PORT
     };
 }
 
 function base_path() {
     return location.pathname.replace(/\/[^\/]*$/, '/');
 }