Add some OWNERS to build

Add some OWNERS to build

By request -- if you land here and feel qualified to review build/
(or a subdir) please feel encouraged to send a CL to add yourself to
OWNERS. The initial list was selected simply to avoid having the
reviews sent unnecessarily to top-level src/ OWNERS.

R=cpu@chromium.org,cjhopman@chromium.org,thakis@chromium.org

Committed: https://crrev.com/490b0ea5ff99a3a35347f490bdc63495198aca8d
Cr-Commit-Position: refs/heads/master@{#307346}

[cjhopman, 2014-12-08 20:56:17]

lgtm

[cpu_(ooo_6.6-7.5), 2014-12-08 21:07:12]

lgtm

[scottmg, 2014-12-08 21:16:13]

The CQ bit was checked by scottmg@chromium.org

[commit-bot: I haz the power, 2014-12-08 21:16:59]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/786093002/1

[Nico, 2014-12-08 21:51:34]

lgtm

[commit-bot: I haz the power, 2014-12-08 21:55:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-12-08 21:56:15]

Patchset 1 (id:??) landed as
https://crrev.com/490b0ea5ff99a3a35347f490bdc63495198aca8d
Cr-Commit-Position: refs/heads/master@{#307346}