The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d1d249ede7fe09c9d6fd2aacccec764987c323a0

commit d1d249ede7fe09c9d6fd2aacccec764987c323a0
Author: hunyadym <hunyadym@chromium.org>
Date: Tue Mar 07 14:00:28 2017

Save Play user id when ARC user gets a Managed Google Play account

Chrome OS stores the user id it receives from DM Server in order to
later be able to use it for reporting the account activity.

BUG=694304

Review-Url: https://codereview.chromium.org/2704113003
Cr-Commit-Position: refs/heads/master@{#455065}

[modify] https://crrev.com/d1d249ede7fe09c9d6fd2aacccec764987c323a0/chrome/browser/chromeos/arc/arc_session_manager.cc
[modify] https://crrev.com/d1d249ede7fe09c9d6fd2aacccec764987c323a0/chrome/browser/chromeos/arc/auth/arc_active_directory_enrollment_token_fetcher.cc
[modify] https://crrev.com/d1d249ede7fe09c9d6fd2aacccec764987c323a0/chrome/browser/chromeos/arc/auth/arc_active_directory_enrollment_token_fetcher_browsertest.cc
[modify] https://crrev.com/d1d249ede7fe09c9d6fd2aacccec764987c323a0/chrome/browser/chromeos/profiles/profile_helper.h
[modify] https://crrev.com/d1d249ede7fe09c9d6fd2aacccec764987c323a0/chrome/common/pref_names.cc
[modify] https://crrev.com/d1d249ede7fe09c9d6fd2aacccec764987c323a0/chrome/common/pref_names.h

While doing that, it might be worthwhile to include a check whether the device has been deprovisioned, see crbug.com/775474.