Add POSIX shared memory support for Mac
This re-adds POSIX shared memory support on Mac. This
is for use in the sharing of field trials using shared memory. You
can see the design doc for this project at:
https://docs.google.com/document/d/1mTjD99PchmCGYtLvpxaXFObVnid1zmXIsWBI7GjuJgo/
and the motivation for this change under "Port to other platforms".
NOTE: turning on NOPRESUBMIT because this re-adds some banned calls to AllowIO.
BUG=671228
NOPRESUBMIT=true
Review-Url: https://codereview.chromium.org/2555483002
Cr-Commit-Position: refs/heads/master@{#437709}
CrOS-Libchrome-Original-Commit: 2fc6cf8d316d1f452dd27dbd0d886aef15b69659
6 files changed