Update AbstractWorker, Worker and SharedWorker to match the spec

Source/core/workers/AbstractWorker.idl

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple 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.
@@ skipping 12 matching lines @@
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * 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.
  */
 
 [
-    NoInterfaceObject,
-    ActiveDOMObject,
-    EventTarget
+    NoInterfaceObject
 ] interface AbstractWorker {
-
     attribute EventListener onerror;
-
-    void addEventListener(DOMString type,
-                          EventListener listener,
-                          optional boolean useCapture);
-    void removeEventListener(DOMString type,
-                             EventListener listener,
-                             optional boolean useCapture);
-    [RaisesException] boolean dispatchEvent(Event evt);
 };
 
+Worker implements AbstractWorker;
+SharedWorker implements AbstractWorker;