Add slots for navigator.serviceWorker.installing and active.

Source/modules/serviceworkers/ServiceWorkerContainer.idl

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 [
     RuntimeEnabled=ServiceWorker
 ] interface ServiceWorkerContainer {
+    [Unforgeable] readonly attribute ServiceWorker active;
+    [Unforgeable] readonly attribute ServiceWorker controller;
+    [Unforgeable] readonly attribute ServiceWorker installing;
     [Unforgeable] readonly attribute ServiceWorker waiting;
-    // FIXME: controller should be unforgeable
-    readonly attribute ServiceWorker controller;
 
     [CallWith=ScriptState] readonly attribute Promise ready;
 
     [CallWith=ScriptState, ImplementedAs=registerServiceWorker] Promise register(DOMString url, optional Dictionary options);
     [CallWith=ScriptState, ImplementedAs=unregisterServiceWorker] Promise unregister(optional DOMString scope);
 };