Expose events in workers as per latest DOM specification

Source/core/events/Event.idl

 /*
  * Copyright (C) 2006, 2007, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 // Introduced in DOM Level 2:
 [
     WillBeGarbageCollected,
     Custom=Wrap,
     EventConstructor,
+    Exposed=Window&Worker
 ] interface Event {
 
     // DOM PhaseType
     const unsigned short NONE                = 0;
     const unsigned short CAPTURING_PHASE     = 1;
     const unsigned short AT_TARGET           = 2;
     const unsigned short BUBBLING_PHASE      = 3;
 
     // Reverse-engineered from Netscape
     const unsigned short MOUSEDOWN           = 1;
@@ skipping 31 matching lines @@
     readonly attribute boolean defaultPrevented;
     void stopImmediatePropagation();
 
     // IE Extensions
     [MeasureAs=EventSrcElement] readonly attribute EventTarget srcElement;
     [CallWith=ExecutionContext, ImplementedAs=legacyReturnValue, MeasureAs=EventReturnValue] attribute boolean returnValue;
     [MeasureAs=EventCancelBubble] attribute boolean cancelBubble;
     [MeasureAs=EventPath] readonly attribute NodeList path;
     [Custom=Getter, MeasureAs=EventClipboardData] readonly attribute DataTransfer clipboardData;
 };