Revert of Wallpaper manager now observing user child user status to update default wallpaper. (patchset #2 id:20001 of https://codereview.chromium.org/
952853002/)
Reason for revert:
MultiUserNotificationBlockerChromeOSTest is failing after this CL (see issue 463049).
Original issue's description:
> Wallpaper manager now observing user child user status to update default wallpaper.
>
> BUG=461282
>
> Committed: https://crrev.com/
c3a3f671f8e0c5777c6bc825f21d61c6bcafbec3
> Cr-Commit-Position: refs/heads/master@{#318666}
TBR=bshe@chromium.org,skuhne@chromium.org,merkulova@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=461282
Review URL: https://codereview.chromium.org/
966333004
Cr-Commit-Position: refs/heads/master@{#318669}