PPAPI: Make blocking completion callbacks work.

ppapi/thunk/ppb_directory_reader_thunk.cc

 // 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.
 
 #include "ppapi/c/dev/ppb_directory_reader_dev.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_errors.h"
+#include "ppapi/shared_impl/tracked_callback.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/thunk.h"
 #include "ppapi/thunk/ppb_directory_reader_api.h"
 #include "ppapi/thunk/resource_creation_api.h"
 
 namespace ppapi {
 namespace thunk {
 
 namespace {
 
@@ skipping 13 matching lines @@
   return PP_FromBool(enter.succeeded());
 }
 
 int32_t GetNextEntry(PP_Resource directory_reader,
                      PP_DirectoryEntry_Dev* entry,
                      PP_CompletionCallback callback) {
   EnterResource<PPB_DirectoryReader_API> enter(
       directory_reader, callback, true);
   if (enter.failed())
     return enter.retval();
-  return enter.SetResult(enter.object()->GetNextEntry(entry, callback));
+  return enter.SetResult(enter.object()->GetNextEntry(entry, enter.callback()));
 }
 
 const PPB_DirectoryReader_Dev g_ppb_directory_reader_thunk = {
   &Create,
   &IsDirectoryReader,
   &GetNextEntry
 };
 
 }  // namespace
 
 const PPB_DirectoryReader_Dev_0_5* GetPPB_DirectoryReader_Dev_0_5_Thunk() {
   return &g_ppb_directory_reader_thunk;
 }
 
 }  // namespace thunk
 }  // namespace ppapi