Revert of Disable RunMultiThread_DirectRenderer on Windows

Revert of Disable RunMultiThread_DirectRenderer on Windows (patchset #2 id:20001 of https://codereview.chromium.org/1308993006/ )

Reason for revert:
Test is fixed.

Original issue's description:
> Disable LayerTreeHostAnimationTestPendingTreeAnimatesFirstCommit
>
> BUG=527087
> CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
>
> Committed: https://crrev.com/4b7f32d2326449a03c7d5c171939ac0b349af257
> Cr-Commit-Position: refs/heads/master@{#346738}

TBR=pvalenzuela@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=527087
Committed: https://crrev.com/aa998094ad4bd5c60c2519cb61119921537d61c5
Cr-Commit-Position: refs/heads/master@{#346752}

[danakj, 2015-09-01 22:06:57]

Created Revert of Disable RunMultiThread_DirectRenderer on Windows

[commit-bot: I haz the power, 2015-09-01 22:07:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1308273009/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1308273009/1

[commit-bot: I haz the power, 2015-09-01 22:08:21]

Committed patchset #1 (id:1)

[pval...(no longer on Chromium), 2015-09-01 22:08:37]

thanks for fixing the flake

[pval...(no longer on Chromium), 2015-09-01 22:08:42]

lgtm

[commit-bot: I haz the power, 2015-09-01 22:08:57]

Patchset 1 (id:??) landed as
https://crrev.com/aa998094ad4bd5c60c2519cb61119921537d61c5
Cr-Commit-Position: refs/heads/master@{#346752}