Convert to new enter method

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/thunk/common.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 {
 
 PP_Resource Create(PP_Resource directory_ref) {
   EnterFunctionGivenResource<ResourceCreationAPI> enter(directory_ref, true);
   if (enter.failed())
     return 0;
   return enter.functions()->CreateDirectoryReader(directory_ref);
 }
 
 PP_Bool IsDirectoryReader(PP_Resource resource) {
   EnterResource<PPB_DirectoryReader_API> enter(resource, false);
   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, true);
+  EnterResource<PPB_DirectoryReader_API> enter(
+      directory_reader, callback, true);
   if (enter.failed())
-    return MayForceCallback(callback, PP_ERROR_BADRESOURCE);
-  int32_t result = enter.object()->GetNextEntry(entry, callback);
-  return MayForceCallback(callback, result);
+    return enter.retval();
+  return enter.SetResult(enter.object()->GetNextEntry(entry, 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