Adding support for DOM3 KeyboardEvents Code in KeyboardEvents

Source/core/events/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,
  * 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.
  */
 
 [
     EventConstructor,
 ] interface KeyboardEvent : UIEvent {
     const unsigned long DOM_KEY_LOCATION_STANDARD = 0x00;
     const unsigned long DOM_KEY_LOCATION_LEFT     = 0x01;
     const unsigned long DOM_KEY_LOCATION_RIGHT    = 0x02;
     const unsigned long DOM_KEY_LOCATION_NUMPAD   = 0x03;
 
+    readonly attribute DOMString                                        code;

[Rick Byers, 2015/01/20 14:49:56]

This should be initialized by the constructor as well (and there should be a
test that verifies it can be set with a constructor).

Please put your new API surface area behind a RuntimeEnabledFeature
(http://www.chromium.org/blink/runtime-enabled-features) that's initially
'experimental'.  Once all chromium/blink CLs have landed and some basic compat
testing has been done across platforms, we can switch it to 'Stable'.  Worst
case and we discover some compat breakage we can just flip it back to
'Experimental' (rather than have to revert your CLs) while we address issues.

[Habib Virji, 2015/01/22 16:01:30]

Are you refering to below initKeyboardEvent? My understanding is wez has
suggested to be removed, as this interface is obsolete. If refering to
KeyboardEvent() constructors, it does initialize code value, except for the one
initialized by initiKeyboardEvent.  

Have added this API changes in runtime enabled feature. 

     [InitializedByEventConstructor] readonly attribute DOMString        keyIdentifier;
     [InitializedByEventConstructor] readonly attribute unsigned long    location;
     [ImplementedAs=location, DeprecateAs=KeyboardEventKeyLocation, InitializedByEventConstructor] readonly attribute unsigned long keyLocation; // Deprecated.
     [InitializedByEventConstructor] readonly attribute boolean          ctrlKey;
     [InitializedByEventConstructor] readonly attribute boolean          shiftKey;
     [InitializedByEventConstructor] readonly attribute boolean          altKey;
     [InitializedByEventConstructor] readonly attribute boolean          metaKey;
     [InitializedByEventConstructor] readonly attribute boolean          repeat;
 
     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 location,
                            [Default=Undefined] optional boolean ctrlKey,
                            [Default=Undefined] optional boolean altKey,
                            [Default=Undefined] optional boolean shiftKey,
                            [Default=Undefined] optional boolean metaKey);
 
     readonly attribute long charCode;
     readonly attribute long keyCode;
     readonly attribute long which;
 };