Revert of CrWinClang: Swarm content_unittests, net_unittests, unit_tests, browser_tests.

Revert of CrWinClang: Swarm content_unittests, net_unittests, unit_tests, browser_tests. (patchset #1 id:1 of https://codereview.chromium.org/859303007/)

Reason for revert:
Didn't work, isolate tests step still throws a MemoryError

Original issue's description:
> CrWinClang: Swarm content_unittests, net_unittests, unit_tests, browser_tests.
>
> Now that isolate archival no longer dies as quickly, this should work.
>
> BUG=446368, 419862
> R=maruel@chromium.org
>
> Committed: https://chromium.googlesource.com/chromium/src/+/c1275273c2674e3b4a12e3e096dc5a6ae02374af

TBR=maruel@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=446368, 419862
Committed: https://crrev.com/5dfdf4f834d542e7d5c81dc2f3fe34fb0265a9f3
Cr-Commit-Position: refs/heads/master@{#312773}

[Nico, 2015-01-23 05:19:44]

Created Revert of CrWinClang: Swarm content_unittests, net_unittests,
unit_tests, browser_tests.

[commit-bot: I haz the power, 2015-01-23 05:20:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/869003004/1

[commit-bot: I haz the power, 2015-01-23 05:22:06]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-23 05:22:59]

Patchset 1 (id:??) landed as
https://crrev.com/5dfdf4f834d542e7d5c81dc2f3fe34fb0265a9f3
Cr-Commit-Position: refs/heads/master@{#312773}

[Nico, 2015-02-10 06:04:43]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/893313006/ by thakis@chromium.org.

The reason for reverting is: Let's try this again now that the clang/win bots
use fastbuild (crbug.com/455966).