GitLab

This CL removes the robot account ID from the refresh token API of
the DeviceOAuth2TokenService as there is a single account in the
DeviceOAuth2TokenService. It also marks as private the
OAuth2TokenManagerDelegate functions that it implements.

Bug: 1028509

Change-Id: I0e6ab3255194d3181f3206304ddd61b3c4abda20
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2022705
Commit-Queue: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737304}