Update permissions for Smart Lock setup app.

Update permissions for Smart Lock setup app.

chrome.browser.openTab allows us to bypass security checks to open
chrome://settings from the app. chrome.tabs is only allowed for extensions, not apps.

BUG=398656
NOTRY=true

Committed: https://crrev.com/f264dce3bcaf59187834def5bc2ceee055429953
Cr-Commit-Position: refs/heads/master@{#301951}

[Tim Song, 2014-10-29 21:23:59]

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

[xiyuan, 2014-10-29 21:25:32]

lgtm

[Tim Song, 2014-10-29 22:08:50]

The CQ bit was checked by tengs@chromium.org

[commit-bot: I haz the power, 2014-10-29 22:10:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/689723005/1

[commit-bot: I haz the power, 2014-10-29 22:13:19]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-29 22:14:00]

Patchset 1 (id:??) landed as
https://crrev.com/f264dce3bcaf59187834def5bc2ceee055429953
Cr-Commit-Position: refs/heads/master@{#301951}