This directory contains the rlbox source from the upstream repo:
https://github.com/PLSysSec/rlbox_sandboxing_api/

Current version: [commit f83fa7f9d3a6510cf59e8eec8eb1578879368f93]

UPDATING:

This in-tree copy can be updated by running
  sh update.sh
from within the third_party/rlbox directory.