The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/daacc0eb68641a8725df1cee29322ce03f5a48e6

commit daacc0eb68641a8725df1cee29322ce03f5a48e6
Author: Owen Min <zmin@chromium.org>
Date: Wed Aug 08 13:36:34 2018

Add an alternative way of setup cloud policy enrollment token on Mac.

MachineLevelUserCloudPolicy enrollment is setup by platform policy. It's
not trivial on Mac as it requires additional software. Add a secondary
simple token setup way.

When the MachineLevelUserCloudPolicyToken policy is not setup. Read the
enrollment token from file.
/Library/Google/Chrome/MachineLevelUserCloudPolicyToken on Chrome.
/Library/Application Support/Chromium/MachineLevelUserCloudPolicyEnrollmentToken
on Chromium

TEST:
1) Open Chrome, make sure MachineLevelUserCloudPolicyToken is not set via
   via chrome://policy. Close Chrome.
2) Edit /Library/Google/Chrome/MachineLevelUserCloudPolicyEnrollmentToken
   to fill a random string.
   (For Chromium it's
   /Library/Application Support/Chromium/MachineLevelUserCloudPolicyEnrollmentToken)
3) Open Chrome, verify the error dialog displayed.
4) Replace the string in 2) with a valid enrollment token.
5) Click "Relaunch Chrome". Chrome is closed and opened with browser window.


Bug:  871523 
Change-Id: I51e111b1f40be2677b7820f0352d4be48c192c32
Reviewed-on: https://chromium-review.googlesource.com/1164387
Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Reviewed-by: Georges Khalil <georgesak@chromium.org>
Commit-Queue: Owen Min <zmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581547}
[modify] https://crrev.com/daacc0eb68641a8725df1cee29322ce03f5a48e6/chrome/browser/policy/browser_dm_token_storage_linux.cc
[modify] https://crrev.com/daacc0eb68641a8725df1cee29322ce03f5a48e6/chrome/browser/policy/browser_dm_token_storage_mac.mm