Linux sandbox: move RestrictClockID() to sandbox/

Linux sandbox: move RestrictClockID() to sandbox/

We move RestrictClockID() from the NaCl NonSFI sandbox to the
main helpers in sandbox/.

BUG=413469
TBR=brettw

Committed: https://crrev.com/fcdfb1094c7db30011101c0442957b8e1b5252d1
Cr-Commit-Position: refs/heads/master@{#294533}

[jln (very slow on Chromium), 2014-09-11 23:50:02]

jln@chromium.org changed reviewers:
+ mdempsky@chromium.org

[jln (very slow on Chromium), 2014-09-11 23:50:07]

Matthew: PTAL!

[mdempsky_google, 2014-09-11 23:55:11]

mdempsky@google.com changed reviewers:
+ mdempsky@google.com

[mdempsky_google, 2014-09-11 23:55:12]

lgtm

[mdempsky, 2014-09-12 00:16:41]

lgtm

[jln (very slow on Chromium), 2014-09-12 00:32:22]

TBR-ing brettw as third-party/ OWNERs which is required because I'm re-adding it
to DEPS.

[jln (very slow on Chromium), 2014-09-12 00:59:07]

The CQ bit was checked by jln@chromium.org

[commit-bot: I haz the power, 2014-09-12 01:03:16]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patchset/563043005/70001

[commit-bot: I haz the power, 2014-09-12 02:51:55]

Committed patchset #5 (id:70001) as fd1f70b8511c7eeb4a2ecc3c568bee4dbf778d75

[commit-bot: I haz the power, 2014-09-12 02:55:12]

Patchset 5 (id:??) landed as
https://crrev.com/fcdfb1094c7db30011101c0442957b8e1b5252d1
Cr-Commit-Position: refs/heads/master@{#294533}