Convert to new enter method

ppapi/thunk/ppb_directory_reader_thunk.cc

Index: ppapi/thunk/ppb_directory_reader_thunk.cc
diff --git a/ppapi/thunk/ppb_directory_reader_thunk.cc b/ppapi/thunk/ppb_directory_reader_thunk.cc
index f03b165227d13efdd970521c3853cb5d4e580e1d..369283ccc10511026b92a4599bb54df16a2f2ea9 100644
--- a/ppapi/thunk/ppb_directory_reader_thunk.cc
+++ b/ppapi/thunk/ppb_directory_reader_thunk.cc
@@ -5,7 +5,6 @@
 #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"
@@ -31,11 +30,11 @@ PP_Bool IsDirectoryReader(PP_Resource resource) {
 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 = {