Convert chromeos_unittests to run exclusively on Swarming

Convert chromeos_unittests to run exclusively on Swarming

0 configs already ran on Swarming
6 used to run locally and were converted:
- chromium.chromiumos.json: Linux ChromiumOS Ozone Tests (1)
- chromium.chromiumos.json: Linux ChromiumOS Tests (1)
- chromium.chromiumos.json: Linux ChromiumOS Tests (dbg)(1)
- chromium.memory.json: Linux Chromium OS ASan LSan Tests (1)
- chromium.webkit.json: Linux ChromiumOS Tests (1)
- chromium.webkit.json: Linux ChromiumOS Tests (dbg)(1)

Ran:
  ./manage.py --convert chromeos_unittests

BUG=98637
Committed: https://crrev.com/b740ceb41acd9e8279638743a9e7d09a0e7ae7d3
Cr-Commit-Position: refs/heads/master@{#336926}

[Reilly Grant (use Gerrit), 2015-06-30 22:55:19]

reillyg@chromium.org changed reviewers:
+ maruel@chromium.org, stevenjb@chromium.org

[Reilly Grant (use Gerrit), 2015-06-30 23:31:47]

Please take a look.

[M-A Ruel, 2015-06-30 23:40:18]

lgtm

(I normally also update build/gn_migration.gypi but it's not a big deal, it can
be done later)

[stevenjb, 2015-06-30 23:49:13]

owner rubberstamp lgtm

[Reilly Grant (use Gerrit), 2015-06-30 23:50:32]

The CQ bit was checked by reillyg@chromium.org

[commit-bot: I haz the power, 2015-06-30 23:50:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1219123002/1

[commit-bot: I haz the power, 2015-07-01 00:00:15]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-01 00:01:23]

Patchset 1 (id:??) landed as
https://crrev.com/b740ceb41acd9e8279638743a9e7d09a0e7ae7d3
Cr-Commit-Position: refs/heads/master@{#336926}