Revert of ash: Add checks for supervised users.

Revert of ash: Add checks for supervised users. (patchset #5 id:80001 of https://codereview.chromium.org/561713002/)

Reason for revert:
This is breaking NotificationApiTest.TestUserGesture, which assumes it starts with an empty notification list.

Somehow this is causing the browser test to be in a state where there is already a notification in the list regarding a supervised user.

Original issue's description:
> ash: Add checks for supervised users.
>
> Propagate the user's supervised state to the ash system
> so that it becomes available for views
>
> https://chromereviews.googleplex.com/79527013/
>
> BUG=394417
>
> Committed: https://crrev.com/8616ac4cf7bd77f53dc001eb9d8d61c6c975eaaa
> Cr-Commit-Position: refs/heads/master@{#294821}

TBR=antrim@chromium.org,derat@chromium.org,jennyz@chromium.org,bauerb@chromium.org,treib@chromium.org,merkulova@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=394417
Committed: https://crrev.com/0b527c1ef9f0794742e8ea004fbaf7ecea2f4cef
Cr-Commit-Position: refs/heads/master@{#294934}

[Ken Rockot(use gerrit already), 2014-09-15 23:16:41]

Created Revert of ash: Add checks for supervised users.

[commit-bot: I haz the power, 2014-09-15 23:32:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/575653002/1

[commit-bot: I haz the power, 2014-09-16 00:00:33]

Committed patchset #1 (id:1) as 8390cdb22fac07ab292d78e42f2b248672b5b1e1

[commit-bot: I haz the power, 2014-09-16 00:04:37]

Patchset 1 (id:??) landed as
https://crrev.com/0b527c1ef9f0794742e8ea004fbaf7ecea2f4cef
Cr-Commit-Position: refs/heads/master@{#294934}