chrome://supervised-user-internals: handle null AccountTrackerService

chrome://supervised-user-internals: handle null AccountTrackerService

This fixes a crash when the page is accessed in guest or incognito mode.

BUG=600236
Committed: https://crrev.com/89f1e2e60059c782353b26fd2f9c7eb00a133810
Cr-Commit-Position: refs/heads/master@{#385449}

[Marc Treib, 2016-04-06 11:16:23]

The CQ bit was checked by treib@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-04-06 11:16:36]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1859393002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1859393002/1

[Marc Treib, 2016-04-06 11:16:45]

treib@chromium.org changed reviewers:
+ bauerb@chromium.org

[Marc Treib, 2016-04-06 11:16:46]

PTAL!

[commit-bot: I haz the power, 2016-04-06 12:55:29]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-04-06 12:55:29]

Dry run: This issue passed the CQ dry run.

[Bernhard Bauer, 2016-04-06 13:40:29]

lgtm

[Marc Treib, 2016-04-06 13:42:06]

The CQ bit was checked by treib@chromium.org

[commit-bot: I haz the power, 2016-04-06 13:42:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1859393002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1859393002/1

[commit-bot: I haz the power, 2016-04-06 13:47:07]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-04-06 13:48:18]

Description was changed from

==========
chrome://supervised-user-internals: handle null AccountTrackerService

This fixes a crash when the page is accessed in guest or incognito mode.

BUG=600236
==========

to

==========
chrome://supervised-user-internals: handle null AccountTrackerService

This fixes a crash when the page is accessed in guest or incognito mode.

BUG=600236

Committed: https://crrev.com/89f1e2e60059c782353b26fd2f9c7eb00a133810
Cr-Commit-Position: refs/heads/master@{#385449}
==========

[commit-bot: I haz the power, 2016-04-06 13:48:19]

Patchset 1 (id:??) landed as
https://crrev.com/89f1e2e60059c782353b26fd2f9c7eb00a133810
Cr-Commit-Position: refs/heads/master@{#385449}