Update WebKit IDLs after chrome roll.

html/track/TextTrackRegion.idl

 /*
  * Copyright (C) 2013 Google 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. 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. 
  */
 
 [
     Conditional=VIDEO_TRACK & WEBVTT_REGIONS,
     V8EnabledAtRuntime=webkitVideoTrack,
-    JSGenerateToNativeObject,
     Constructor()
 ] interface TextTrackRegion {
     readonly attribute TextTrack track;
 
     attribute DOMString id;
     attribute double width
         setter raises (DOMException);
     attribute long height
         setter raises (DOMException);
     attribute double regionAnchorX
         setter raises (DOMException);
     attribute double regionAnchorY
         setter raises (DOMException);
     attribute double viewportAnchorX
         setter raises (DOMException);
     attribute double viewportAnchorY
         setter raises (DOMException);
     attribute DOMString scroll
         setter raises (DOMException);
 };