Fix force policy installation of the removed pref-installed extension

Fix force policy installation of the removed pref-installed extension

This fixes the issue with the extension not being force-installed
through the admin policy when it was previously installed by the
external preference and then manually removed by the user.

BUG=651197
TEST=Unit test

Committed: https://crrev.com/6699afb688a0c3b9d6eb85915bc475a3a3b46716
Cr-Commit-Position: refs/heads/master@{#424245}

[emaxx, 2016-10-10 19:09:06]

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

[commit-bot: I haz the power, 2016-10-10 19:09:22]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[emaxx, 2016-10-10 19:17:00]

emaxx@chromium.org changed reviewers:
+ asargent@chromium.org

[emaxx, 2016-10-10 19:17:01]

Antony, PTAL.

[commit-bot: I haz the power, 2016-10-10 19:45:51]

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

[commit-bot: I haz the power, 2016-10-10 19:45:52]

Dry run: This issue passed the CQ dry run.

[asargent_no_longer_on_chrome, 2016-10-10 20:01:15]

lgtm

[emaxx, 2016-10-10 21:15:55]

The CQ bit was checked by emaxx@chromium.org

[commit-bot: I haz the power, 2016-10-10 21:16:39]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-10 21:22:38]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-10 21:24:06]

Description was changed from

==========
Fix force policy installation of the removed pref-installed extension

This fixes the issue with the extension not being force-installed
through the admin policy when it was previously installed by the
external preference and then manually removed by the user.

BUG=651197
TEST=Unit test
==========

to

==========
Fix force policy installation of the removed pref-installed extension

This fixes the issue with the extension not being force-installed
through the admin policy when it was previously installed by the
external preference and then manually removed by the user.

BUG=651197
TEST=Unit test

Committed: https://crrev.com/6699afb688a0c3b9d6eb85915bc475a3a3b46716
Cr-Commit-Position: refs/heads/master@{#424245}
==========

[commit-bot: I haz the power, 2016-10-10 21:24:07]

Patchset 1 (id:??) landed as
https://crrev.com/6699afb688a0c3b9d6eb85915bc475a3a3b46716
Cr-Commit-Position: refs/heads/master@{#424245}