Populates sourceDevice attribute into MouseEvent

Source/core/events/MouseEvent.idl

 /*
  * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
  *
  * 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
@@ skipping 35 matching lines @@
                                        [Default=Undefined] optional long screenX,
                                        [Default=Undefined] optional long screenY,
                                        [Default=Undefined] optional long clientX,
                                        [Default=Undefined] optional long clientY,
                                        [Default=Undefined] optional boolean ctrlKey,
                                        [Default=Undefined] optional boolean altKey,
                                        [Default=Undefined] optional boolean shiftKey,
                                        [Default=Undefined] optional boolean metaKey,
                                        [Default=Undefined] optional unsigned short button,
                                        [Default=Undefined] optional EventTarget? relatedTarget);
+                                       
+    [RuntimeEnabled=InputDevice, CallWith=ScriptState] void initMouseEvent([Default=Undefined] optional DOMString type,
+                                       [Default=Undefined] optional boolean bubbles,
+                                       [Default=Undefined] optional boolean cancelable,
+                                       [Default=Undefined] optional Window? view,
+                                       [Default=Undefined] optional long detail,
+                                       [Default=Undefined] optional long screenX,
+                                       [Default=Undefined] optional long screenY,
+                                       [Default=Undefined] optional long clientX,
+                                       [Default=Undefined] optional long clientY,
+                                       [Default=Undefined] optional boolean ctrlKey,
+                                       [Default=Undefined] optional boolean altKey,
+                                       [Default=Undefined] optional boolean shiftKey,
+                                       [Default=Undefined] optional boolean metaKey,
+                                       [Default=Undefined] optional unsigned short button,
+                                       [Default=Undefined] optional EventTarget? relatedTarget,
+                                       [Default=Undefined] InputDevice? sourceDevice);                                   

[Rick Byers, 2015/06/23 00:55:57]

Any chance the bindings generator is smart enough to let you add this as
'optional InputDevice? ...' on the above method, even though InputDevice is
RuntimeEnabled?  That would be simpler if it works.  Otherwise temporarily
adding another overload is fine, and we can remove it once InputDevice is
enabled by default.

 
     // Pointer Lock
     // https://dvcs.w3.org/hg/pointerlock/raw-file/default/index.html#extensions-to-the-mouseevent-interface
     [MeasureAs=MouseEventMovementX] readonly attribute long movementX;
     [MeasureAs=MouseEventMovementY] readonly attribute long movementY;
 
     // Non-standard
     [MeasureAs=MouseEventOffsetX] readonly attribute long offsetX;
     [MeasureAs=MouseEventOffsetY] readonly attribute long offsetY;
     [MeasureAs=MouseEventX] readonly attribute long x;
     [MeasureAs=MouseEventY] readonly attribute long y;
     [MeasureAs=MouseEventFromElement] readonly attribute Node fromElement;
     [MeasureAs=MouseEventToElement] readonly attribute Node toElement;
     [MeasureAs=MouseEventWhich] readonly attribute long which;
     [DeprecateAs=PrefixedMouseEventMovementX, ImplementedAs=movementX] readonly attribute long webkitMovementX;
     [DeprecateAs=PrefixedMouseEventMovementY, ImplementedAs=movementY] readonly attribute long webkitMovementY;
 
     // FIXME: dataTransfer belongs on the DragEvent interface. crbug.com/498504
     readonly attribute DataTransfer dataTransfer;
 };