[Ozone-Drm] Change file locking from Posix to BSD style

[Ozone-Drm] Change file locking from Posix to BSD style

Frecon requires BSD style file locks since the lock needs to be held
past forking. So we also need to change the Ozone side since Posix and
BSD locks don't mix.

BUG=463665
Committed: https://crrev.com/ad432deba307c28a34cac8b6da0dd5200ead1236
Cr-Commit-Position: refs/heads/master@{#321400}

[dnicoara, 2015-03-19 16:16:20]

dnicoara@chromium.org changed reviewers:
+ spang@chromium.org

[spang, 2015-03-19 16:53:49]

lgtm

[dnicoara, 2015-03-19 18:28:21]

The CQ bit was checked by dnicoara@chromium.org

[commit-bot: I haz the power, 2015-03-19 18:28:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1007993007/1

[commit-bot: I haz the power, 2015-03-19 18:51:27]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-19 18:52:19]

Patchset 1 (id:??) landed as
https://crrev.com/ad432deba307c28a34cac8b6da0dd5200ead1236
Cr-Commit-Position: refs/heads/master@{#321400}