Clean up references to the "active user" in the User Manager.

Clean up references to the "active user" in the User Manager.

The active user is always Guest. This is dead code from way back when
the User Manager was displayed under a specific, regular profile.

BUG=NONE

Committed: https://crrev.com/64c6c7071fcb28e8b80ea392f2cd891938ad4fb9
Cr-Commit-Position: refs/heads/master@{#311339}

[noms (inactive), 2015-01-13 21:04:04]

noms@chromium.org changed reviewers:
+ mlerman@chromium.org

[noms (inactive), 2015-01-13 21:04:04]

Cleaning up some nonsensical code from eons ago. Please take a look. Thanks!

[Mike Lerman, 2015-01-13 21:12:22]

lgtm!

[noms (inactive), 2015-01-13 21:15:35]

The CQ bit was checked by noms@chromium.org

[commit-bot: I haz the power, 2015-01-13 21:16:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/788993006/1

[commit-bot: I haz the power, 2015-01-13 21:58:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-13 22:01:30]

Patchset 1 (id:??) landed as
https://crrev.com/64c6c7071fcb28e8b80ea392f2cd891938ad4fb9
Cr-Commit-Position: refs/heads/master@{#311339}