[Background Sync] Align exposed API with spec

third_party/WebKit/LayoutTests/http/tests/background_sync/resources/interfaces-worker.js

 importScripts('/resources/testharness.js');
 importScripts('/resources/testharness-helpers.js');
 
 test(function() {
     assert_own_property(self, 'SyncManager', 'SyncManager needs to be exposed as a global.');
     assert_idl_attribute(registration, 'sync', 'One-shot SyncManager needs to be exposed on the registration.');
 
     assert_inherits(registration.sync, 'register');
-    assert_inherits(registration.sync, 'getRegistration');
-    assert_inherits(registration.sync, 'getRegistrations');
-    assert_inherits(registration.sync, 'permissionState');
+    assert_inherits(registration.sync, 'getTags');
 
 }, 'SyncManager should be exposed and have the expected interface.');
 
 test(function() {
-    assert_own_property(self, 'SyncRegistration', 'SyncRegistration needs to be exposed as a global.');
-
-    // FIXME: Assert existence of the attributes when they are properly
-    // exposed in the prototype chain. https://crbug.com/43394
-    assert_own_property(SyncRegistration.prototype, 'finished');
-    assert_own_property(SyncRegistration.prototype, 'unregister');
-    assert_own_property(SyncRegistration.prototype, 'tag');
-
-}, 'SyncRegistration should be exposed and have the expected interface.');
-
-test(function() {
     assert_own_property(self, 'SyncEvent');
 
-    assert_will_be_idl_attribute(SyncEvent.prototype, 'registration');
+    assert_will_be_idl_attribute(SyncEvent.prototype, 'tag');
 
     // SyncEvent should be extending ExtendableEvent.
     assert_inherits(SyncEvent.prototype, 'waitUntil');
 
 }, 'SyncEvent should be exposed and have the expected interface.');