CRX FileSystem Pepper private API

ppapi/thunk/ppb_file_ref_thunk.cc

Index: ppapi/thunk/ppb_file_ref_thunk.cc
diff --git a/ppapi/thunk/ppb_file_ref_thunk.cc b/ppapi/thunk/ppb_file_ref_thunk.cc
index 3c56c5cabc3cfbea44e6ca15773bf0f965f55481..b74c00b87be988fe96c194a6c2c86ddcde63ddaf 100644
--- a/ppapi/thunk/ppb_file_ref_thunk.cc
+++ b/ppapi/thunk/ppb_file_ref_thunk.cc
@@ -7,6 +7,7 @@
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/private/ppb_file_ref_private.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
 #include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/shared_impl/tracked_callback.h"
 #include "ppapi/thunk/enter.h"
@@ -24,10 +25,19 @@ typedef EnterResource<PPB_FileRef_API> EnterFileRef;
 
 PP_Resource Create(PP_Resource file_system, const char* path) {
   ppapi::ProxyAutoLock lock;
+
+  // Make sure the file_system is one of the expected types.
   EnterResourceNoLock<PPB_FileSystem_API> enter_file_system(file_system, true);
-  if (enter_file_system.failed())
+  EnterResourceNoLock<PPB_Ext_CrxFileSystem_Private_API> enter_crxfs(
+      file_system, true);
+  if (enter_file_system.failed() && enter_crxfs.failed())
     return 0;
-  PP_Instance instance = enter_file_system.resource()->pp_instance();
+
+  // Since file_system is either type of filesystem above, we don't need to
+  // check null-ness below.
+  Resource* res = PpapiGlobals::Get()->GetResourceTracker()->
+      GetResource(file_system);
+  PP_Instance instance = res->pp_instance();
   EnterResourceCreationNoLock enter(instance);
   if (enter.failed())
     return 0;