Look for Owner key in both private and public slots

Look for Owner key in both private and public slots

As a part of migrating away from NSS, CrOS is going to start
generating the device Owner keypair using Chaps, which is
exposed to the browser via the TPM-backed PK11 token that gets
loaded into each user's private NSS PK11 slot. To support the
current mode of operation as well as the new, make
OwnerSettingsServiceChromeOS check both slots for the key.

BUG=422036
TEST=unit test, ownership autotests
R=stevenjb

Committed: https://crrev.com/c19bb4deef7aa916cbfb3d4fbbb5e7f85c19ce6b
Cr-Commit-Position: refs/heads/master@{#300292}

[Chris Masone, 2014-10-17 20:14:30]

Steven, I think you're an OWNER of this code? I can find someone else to review
if you're not appropriate.

[stevenjb, 2014-10-20 16:02:46]

stevenjb@chromium.org changed reviewers:
+ ygorshenin@chromium.org

[stevenjb, 2014-10-20 16:02:47]

+ygorshenin@ who is the owner for c/b/chromeos/ownership (which I am not
familiar with)
owner lgtm for c/b/chromeos/settings/

[ygorshenin1, 2014-10-20 17:10:24]

chrome/browser/chromeos/ownership/ lgtm.

[Chris Masone, 2014-10-20 17:25:26]

The CQ bit was checked by cmasone@chromium.org

[commit-bot: I haz the power, 2014-10-20 17:26:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/660343002/1

[commit-bot: I haz the power, 2014-10-20 17:38:57]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-20 17:39:37]

Patchset 1 (id:??) landed as
https://crrev.com/c19bb4deef7aa916cbfb3d4fbbb5e7f85c19ce6b
Cr-Commit-Position: refs/heads/master@{#300292}