Approving merge to M69 branch 3497, pls merge ASAP. Thank you.

Merged here : https://chromium-review.googlesource.com/c/chromium/src/+/1145627

Thanks.

Oops, meant here: https://chromium-review.googlesource.com/c/chromium/src/+/1155347

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/ecc739b864d0a37661ce18e4e37c5677b4d9c79c

commit ecc739b864d0a37661ce18e4e37c5677b4d9c79c
Author: Georges Khalil <georgesak@chromium.org>
Date: Tue Jul 31 01:02:11 2018

Change Mac OS token location and file name.

This CL has 2 changes:
- Change location to Google Policy/Enrollment
- Derive filename from client ID (in case the home directory is mounted remotely)

Change-Id: I5b3acafd20119f79deef24fb44e3e0514c693311
Reviewed-on: https://chromium-review.googlesource.com/1145627
Commit-Queue: Georges Khalil <georgesak@chromium.org>
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Reviewed-by: Owen Min <zmin@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#577410}(cherry picked from commit 43be30f47adc41bcfe939fc0cd03f0479dc0efb8)
Bug:  869046 
Reviewed-on: https://chromium-review.googlesource.com/1155347
Reviewed-by: Georges Khalil <georgesak@chromium.org>
Cr-Commit-Position: refs/branch-heads/3497@{#257}
Cr-Branched-From: 271eaf50594eb818c9295dc78d364aea18c82ea8-refs/heads/master@{#576753}
[modify] https://crrev.com/ecc739b864d0a37661ce18e4e37c5677b4d9c79c/chrome/browser/policy/browser_dm_token_storage.h
[modify] https://crrev.com/ecc739b864d0a37661ce18e4e37c5677b4d9c79c/chrome/browser/policy/browser_dm_token_storage_mac.mm
[modify] https://crrev.com/ecc739b864d0a37661ce18e4e37c5677b4d9c79c/chrome/browser/policy/browser_dm_token_storage_mac_unittest.cc