Update PPAPI IDL generator to define versioned structs, and unversioned typedef.

ppapi/api/private/ppb_file_ref_private.idl

-/* Copyright (c) 2011 The Chromium Authors. All rights reserved.
+/* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /* This file contains the <code>PPB_FileRefPrivate</code> interface. */
 label Chrome {
   M15 = 0.1
 };
 
 /* PPB_FileRefPrivate interface */
 interface PPB_FileRefPrivate {
   /**
    * GetAbsolutePath() returns the absolute path of the file.
    *
    * @param[in] file_ref A <code>PP_Resource</code> corresponding to a file
    * reference.
    *
    * @return A <code>PP_Var</code> containing the absolute path of the file.
    */
   PP_Var GetAbsolutePath([in] PP_Resource file_ref);
 };