PPAPI: Force async callback invocation option.

ppapi/thunk/ppb_directory_reader_thunk.cc

Index: ppapi/thunk/ppb_directory_reader_thunk.cc
===================================================================
--- ppapi/thunk/ppb_directory_reader_thunk.cc	(revision 91178)
+++ ppapi/thunk/ppb_directory_reader_thunk.cc	(working copy)
@@ -5,8 +5,9 @@
 #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/enter.h"
 #include "ppapi/thunk/ppb_directory_reader_api.h"
 #include "ppapi/thunk/resource_creation_api.h"
 
@@ -32,8 +33,9 @@
                      PP_CompletionCallback callback) {
   EnterResource<PPB_DirectoryReader_API> enter(directory_reader, true);
   if (enter.failed())
-    return PP_ERROR_BADRESOURCE;
-  return enter.object()->GetNextEntry(entry, callback);
+    return MayForceCallback(callback, PP_ERROR_BADRESOURCE);
+  int32_t result = enter.object()->GetNextEntry(entry, callback);
+  return MayForceCallback(callback, result);
 }
 
 const PPB_DirectoryReader_Dev g_ppb_directory_reader_thunk = {