Supervised user blacklist: Make the cmdline flag an enable/disable type.

Supervised user blacklist: Make the cmdline flag an enable/disable value type.

This gives the flag a possible value of "default", which will allow us to enable the feature for some users who haven't explicitly opted in/out.

BUG=410824
Committed: https://crrev.com/63b9dc02b9b2516202e27b0f0555a37005bc5eab
Cr-Commit-Position: refs/heads/master@{#297925}

[Marc Treib, 2014-10-01 14:31:12]

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

[Marc Treib, 2014-10-01 14:31:13]

PTAL!

[Bernhard Bauer, 2014-10-01 14:32:46]

lgtm

[Marc Treib, 2014-10-01 14:33:36]

The CQ bit was checked by treib@chromium.org

[commit-bot: I haz the power, 2014-10-01 14:33:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/611233005/1

[commit-bot: I haz the power, 2014-10-01 15:24:39]

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

[commit-bot: I haz the power, 2014-10-01 15:24:40]

Try jobs failed on following builders:
  android_dbg_tests_recipe on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/android_dbg_tes...)

[Marc Treib, 2014-10-01 15:35:16]

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

[Marc Treib, 2014-10-01 15:35:17]

+asvitkine: Once again, trivial addition to histograms.xml.
Thanks!

[Alexei Svitkine (slow), 2014-10-02 20:48:25]

The CQ bit was checked by asvitkine@chromium.org

[Alexei Svitkine (slow), 2014-10-02 20:48:26]

lgtm

[commit-bot: I haz the power, 2014-10-02 20:50:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/611233005/20001

[commit-bot: I haz the power, 2014-10-02 22:30:24]

Committed patchset #2 (id:20001) as 58e5d4fbbcda3c2188bcbb66ec6229c1d1d21fa2

[commit-bot: I haz the power, 2014-10-02 22:31:07]

Patchset 2 (id:??) landed as
https://crrev.com/63b9dc02b9b2516202e27b0f0555a37005bc5eab
Cr-Commit-Position: refs/heads/master@{#297925}