Always force the bounds of the empty pathref.

Chrome's TSAN bots are seeing various races on the bounds of the empty
path ref, and it's a simple fix to just force them on creation.  In
fact, we used to do this for this very reason, but for some reason it
looks like I decided it wasn't necessary.  Maybe not, but it certainly
doesn't hurt, and it's nice to keep TSAN happy.

Reminder to self: merge this into M39 branch too.

BUG=418299
R=fmalita@chromium.org, robertphillips@google.com, mtklein@google.com

Author: mtklein@chromium.org

Review URL: https://codereview.chromium.org/603503003
1 file changed