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

ppapi/thunk/ppb_buffer_thunk.cc

 // Copyright (c) 2011 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.
 
 #include "ppapi/c/dev/ppb_buffer_dev.h"
 #include "ppapi/thunk/thunk.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_buffer_api.h"
 #include "ppapi/thunk/resource_creation_api.h"
 
@@ skipping 39 matching lines @@
 const PPB_Buffer_Dev g_ppb_buffer_thunk = {
   &Create,
   &IsBuffer,
   &Describe,
   &Map,
   &Unmap,
 };
 
 }  // namespace
 
-const PPB_Buffer_Dev* GetPPB_Buffer_Dev_Thunk() {
+const PPB_Buffer_Dev_0_4* GetPPB_Buffer_Dev_0_4_Thunk() {
   return &g_ppb_buffer_thunk;
 }
 
 }  // namespace thunk
 }  // namespace ppapi