chromium: Fix userns sandbox patch for version 36.

This fixes build for version 36, which i accidentally broke in commit
f6e31fadd80486cdd68e3ad3d7ae888aa81400b9.

The reason this happened, was that my Hydra didn't pick up the latest
commit and I actually tested and built the parent commit instead of the
update commit.

So, this commit is the real "builds fine, tested" for all channels.

AMEND ME AND SIGN OFF - DO NOT MERGE, HYDRA-PICKUP!