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

ppapi/thunk/ppb_scrollbar_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/thunk/thunk.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_scrollbar_api.h"
 #include "ppapi/thunk/resource_creation_api.h"
 
 namespace ppapi {
@@ skipping 69 matching lines @@
   &IsOverlay,
   &GetValue,
   &SetValue,
   &SetDocumentSize,
   &SetTickMarks,
   &ScrollBy
 };
 
 }  // namespace
 
-const PPB_Scrollbar_Dev* GetPPB_Scrollbar_Dev_Thunk() {
+const PPB_Scrollbar_Dev_0_5* GetPPB_Scrollbar_Dev_0_5_Thunk() {
   return &g_ppb_scrollbar_thunk;
 }
 
 }  // namespace thunk
 }  // namespace ppapi