Revert of Revert of Swarm cc_unittests.

Revert of Revert of Swarm cc_unittests. (patchset #1 id:1 of https://codereview.chromium.org/861173002/)

Reason for revert:
just saw this revert. can't find sergeyv online, and don't see information on what broke. so reverting the revert and watching the tree.

Original issue's description:
> Revert of Swarm cc_unittests. (patchset #6 id:100001 of https://codereview.chromium.org/854743002/)
>
> Reason for revert:
> Failures on chrome.mac
>
> Original issue's description:
> > Swarm cc_unittests.
> >
> > BUG=448877
> >
> > Committed: https://crrev.com/9086ff0072268267bacf28e6098a7b5bd8478982
> > Cr-Commit-Position: refs/heads/master@{#312252}
>
> TBR=maruel@chromium.org,alexst@chromium.org,jam@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=448877
>
> Committed: https://crrev.com/c497f3788bc5007ee3bbe2f6aa1cc101b6d66d8b
> Cr-Commit-Position: refs/heads/master@{#312322}

TBR=maruel@chromium.org,alexst@chromium.org,sergeyv@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=448877
Committed: https://crrev.com/75a28f07d5c54d2c0ea5ad59718038599b4b7287
Cr-Commit-Position: refs/heads/master@{#313294}

[jam, 2015-01-27 17:21:20]

Created Revert of Revert of Swarm cc_unittests.

[commit-bot: I haz the power, 2015-01-27 17:21:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/880803004/1

[commit-bot: I haz the power, 2015-01-27 17:23:02]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-27 17:25:04]

Patchset 1 (id:??) landed as
https://crrev.com/75a28f07d5c54d2c0ea5ad59718038599b4b7287
Cr-Commit-Position: refs/heads/master@{#313294}