Add support for KeyboardEvent.getModifierState()

Source/core/dom/KeyboardEvent.idl

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  * 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,
@@ skipping 12 matching lines @@
 ] interface KeyboardEvent : UIEvent {
 
     [InitializedByEventConstructor] readonly attribute DOMString        keyIdentifier;
     [InitializedByEventConstructor] readonly attribute unsigned long    keyLocation;
     [InitializedByEventConstructor] readonly attribute boolean          ctrlKey;
     [InitializedByEventConstructor] readonly attribute boolean          shiftKey;
     [InitializedByEventConstructor] readonly attribute boolean          altKey;
     [InitializedByEventConstructor] readonly attribute boolean          metaKey;
     readonly attribute boolean          altGraphKey;
 
+    boolean getModifierState(DOMString keyArgument);
+
     // FIXME: this does not match the version in the DOM spec.
     void initKeyboardEvent([Default=Undefined] optional DOMString type,
                            [Default=Undefined] optional boolean canBubble,
                            [Default=Undefined] optional boolean cancelable,
                            [Default=Undefined] optional Window view,
                            [Default=Undefined] optional DOMString keyIdentifier,
                            [Default=Undefined] optional unsigned long keyLocation,
                            [Default=Undefined] optional boolean ctrlKey,
                            [Default=Undefined] optional boolean altKey,
                            [Default=Undefined] optional boolean shiftKey,
                            [Default=Undefined] optional boolean metaKey,
                            [Default=Undefined] optional boolean altGraphKey);
 };