kiosk: Fix bailout shortcut not working.

kiosk: Fix bailout shortcut not working.

Explicitly enable login display before launching kiosk so that
the bailout shortcut key works.

BUG=465561
Committed: https://crrev.com/390c1768aa44713198ed393271d985ba2c628263
Cr-Commit-Position: refs/heads/master@{#320088}

[xiyuan, 2015-03-10 19:37:54]

xiyuan@chromium.org changed reviewers:
+ antrim@chromium.org

[Denis Kuznetsov (DE-MUC), 2015-03-11 11:22:29]

lgtm

[xiyuan, 2015-03-11 15:19:49]

The CQ bit was checked by xiyuan@chromium.org

[commit-bot: I haz the power, 2015-03-11 15:20:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/995763004/1

[commit-bot: I haz the power, 2015-03-11 15:26:18]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-11 15:26:49]

Patchset 1 (id:??) landed as
https://crrev.com/390c1768aa44713198ed393271d985ba2c628263
Cr-Commit-Position: refs/heads/master@{#320088}

[xiyuan, 2015-03-11 17:46:11]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/999143002/ by xiyuan@chromium.org.

The reason for reverting is: Multiple KioskTest becomes flaky after the CL
lands. Revert and investigate..