ServiceWorker: Make APIs that return ServiceWorkerRegistration coin a new JS object (3/3)

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) {
   if (!scope || scope.length == 0)
     return Promise.reject(new Error('tests must define a scope'));
 
   var options = { scope: scope };
   return service_worker_unregister(test, scope)
     .then(function() {
         return navigator.serviceWorker.register(url, options);
@@ skipping 187 matching lines @@
 }
 
 function login_https(test) {
   return test_login(test, 'https://127.0.0.1:8443',
                     'username1s', 'password1s', 'cookie1')
     .then(function() {
         return test_login(test, 'https://localhost:8443',
                           'username2s', 'password2s', 'cookie2');
       });
 }
+
+// Helper for testing with ServiceWorkerRegistration objects. Compares simple
+// attributes defined on the interfaces.
+function assert_registration_equals(actual, expected, description) {
+  assert_class_string(actual, 'ServiceWorkerRegistration', description);
+  ['scope', 'installing', 'waiting', 'active'].forEach(function(attribute) {
+      assert_equals(actual[attribute], expected[attribute],
+                    description + ' Attributes differ: ' + attribute + '.');
+    });
+}
+
+// Asserts that two arrays |actual| and |expected| contain the same set of
+// ServiceWorkerRegistration as determined by assert_registration_equals(). The
+// corresponding elements must occupy corresponding indices in their respective
+// arrays.
+function assert_registration_array_equals(actual, expected, description) {
+  assert_true(Array.isArray(actual), description);
+  assert_equals(actual.length, expected.length, description);
+  actual.forEach(function(value, index) {
+      assert_registration_equals(value, expected[index],
+                                 description + ' :  object[' + index + ']');
+    });
+}