Add unittests for the HostContentSettingsMap's provider for Supervised Users.

Add unittests for the HostContentSettingsMap's provider for Supervised Users.

BUG=455646
Committed: https://crrev.com/fafc200a25ac410af7d7def1c32e9e6526fdfd63
Cr-Commit-Position: refs/heads/master@{#321830}

[knn, 2015-03-23 17:12:14]

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

[knn, 2015-03-23 17:12:15]

Tests for https://codereview.chromium.org/902833003

[Bernhard Bauer, 2015-03-23 17:36:13]

LGTM, thanks!

[knn, 2015-03-23 17:52:10]

The CQ bit was checked by knn@chromium.org

[commit-bot: I haz the power, 2015-03-23 17:52:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1005693005/1

[commit-bot: I haz the power, 2015-03-23 17:59:15]

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

[commit-bot: I haz the power, 2015-03-23 17:59:15]

Try jobs failed on following builders:
  linux_chromium_asan_rel on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[knn, 2015-03-23 19:29:59]

The CQ bit was checked by knn@chromium.org

[commit-bot: I haz the power, 2015-03-23 19:30:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1005693005/1

[commit-bot: I haz the power, 2015-03-23 19:31:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-23 19:32:03]

Patchset 1 (id:??) landed as
https://crrev.com/fafc200a25ac410af7d7def1c32e9e6526fdfd63
Cr-Commit-Position: refs/heads/master@{#321830}