Revert of Convert midi_unittests to run exclusively on Swarming

Revert of Convert midi_unittests to run exclusively on Swarming (patchset #1 id:1 of https://codereview.chromium.org/1208103004/)

Reason for revert:
Suspecting this or https://codereview.chromium.org/1206413002 broke isolate step on Mac ASan 64. Reverting both CLs.

https://build.chromium.org/p/chromium.memory/builders/Mac%20ASan%2064%20Builder/builds/21337

Original issue's description:
> Convert midi_unittests to run exclusively on Swarming
>
> 13 configs already ran on Swarming
> 16 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.fyi.json: CrWinAsan tester
> - chromium.fyi.json: CrWinAsan(dll) tester
> - chromium.fyi.json: Linux Trusty
> - chromium.fyi.json: Linux Trusty (dbg)
> - chromium.linux.json: Cast Linux
> - chromium.memory.fyi.json: Linux ChromeOS MSan Tests
> - chromium.memory.fyi.json: Linux MSan Tests
> - chromium.memory.fyi.json: Linux TSan Tests
> - chromium.memory.json: Linux ASan LSan Tests (1)
> - chromium.memory.json: Linux Chromium OS ASan LSan Tests (1)
> - chromium.memory.json: Mac ASan 64 Tests (1)
> - chromium.webkit.json: Linux ChromiumOS Tests (1)
> - chromium.webkit.json: Linux ChromiumOS Tests (dbg)(1)
>
> Ran:
>   ./manage.py --convert midi_unittests
>
> R=dpranke@chromium.org
> BUG=98637
>
> Committed: https://crrev.com/fd955c285b8196938bd08767de2df019c7029a07
> Cr-Commit-Position: refs/heads/master@{#336264}

TBR=dpranke@chromium.org,maruel@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=98637
Committed: https://crrev.com/ab2eec5f3702548fffc15ea1dbaee7a801d1f7c8
Cr-Commit-Position: refs/heads/master@{#336278}

[Mike Wittman, 2015-06-25 22:31:08]

Created Revert of Convert midi_unittests to run exclusively on Swarming

[commit-bot: I haz the power, 2015-06-25 22:31:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1210933003/1

[commit-bot: I haz the power, 2015-06-25 22:36:27]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-06-25 22:38:31]

Patchset 1 (id:??) landed as
https://crrev.com/ab2eec5f3702548fffc15ea1dbaee7a801d1f7c8
Cr-Commit-Position: refs/heads/master@{#336278}