Delete FunctionGroupBase from Pepper.

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 369283ccc10511026b92a4599bb54df16a2f2ea9..eb5868454d7728a3798bb5ea1f62d8e00f1123a1 100644
--- a/ppapi/thunk/ppb_directory_reader_thunk.cc
+++ b/ppapi/thunk/ppb_directory_reader_thunk.cc
@@ -16,7 +16,11 @@ namespace thunk {
 namespace {
 
 PP_Resource Create(PP_Resource directory_ref) {
-  EnterFunctionGivenResource<ResourceCreationAPI> enter(directory_ref, true);
+  Resource* object =
+      PpapiGlobals::Get()->GetResourceTracker()->GetResource(directory_ref);
+  if (!object)
+    return 0;
+  EnterResourceCreation enter(object->pp_instance());
   if (enter.failed())
     return 0;
   return enter.functions()->CreateDirectoryReader(directory_ref);