PPAPI: Add new PPB_FileRef.MakeDirectory to support exclusive operation

ppapi/proxy/file_ref_resource.cc

Index: ppapi/proxy/file_ref_resource.cc
diff --git a/ppapi/proxy/file_ref_resource.cc b/ppapi/proxy/file_ref_resource.cc
index 7cd96bc60a0685251c888b41c0fe8cae3e05bb38..ec6662ff27a15adde9d3846550b86c4a78338712 100644
--- a/ppapi/proxy/file_ref_resource.cc
+++ b/ppapi/proxy/file_ref_resource.cc
@@ -129,11 +129,11 @@ PP_Resource FileRefResource::GetParent() {
 }
 
 int32_t FileRefResource::MakeDirectory(
-    PP_Bool make_ancestors,
+    int32_t make_directory_flags,
     scoped_refptr<TrackedCallback> callback) {
   Call<PpapiPluginMsg_FileRef_MakeDirectoryReply>(
       BROWSER,
-      PpapiHostMsg_FileRef_MakeDirectory(PP_TRUE == make_ancestors),
+      PpapiHostMsg_FileRef_MakeDirectory(make_directory_flags),
       base::Bind(&FileRefResource::RunTrackedCallback, this, callback));
   return PP_OK_COMPLETIONPENDING;
 }