Revert of Revert of Disable WebGL conformance test on Win8/NVIDIA

Revert of Revert of Disable WebGL conformance test on Win8/NVIDIA (patchset #1 id:1 of https://codereview.chromium.org/1085073002/)

Reason for revert:
Still very flaky on Win Nvidia:

http://test-results.appspot.com/dashboards/flakiness_dashboard.html#testType=webgl_conformance_tests&tests=WebglConformance.conformance_textures_tex_image_and_sub_image_2d_with_array_buffer_view

Original issue's description:
> Revert of Disable WebGL conformance test on Win8/NVIDIA (patchset #3 id:40001 of https://codereview.chromium.org/930423002/)
>
> Reason for revert:
> kbr@ doesn't think this is needed anymore, and it might be a cause of us missing real issues.  I'll try reverting it, and keep an eye on it.
>
> Original issue's description:
> > Disable WebGL conformance test on Win8/NVIDIA
> >
> > The test:
> > conformance_textures_tex_image_and_sub_image_2d_with_array_buffer_view
> >
> > Has been timing out on and off for as long as we have records.
> >
> > BUG=459265
> > NOPRESUBMIT=True
> >
> > Committed: https://crrev.com/777a126ec7c9fbd50c4f62b27de648e5b306fc7d
> > Cr-Commit-Position: refs/heads/master@{#316872}
>
> TBR=zmo@chromium.org,ccameron@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=459265
>
> Committed: https://crrev.com/997ea6c612de165623240c058f9e4e89ced7f702
> Cr-Commit-Position: refs/heads/master@{#325142}

TBR=zmo@chromium.org,ccameron@chromium.org,hendrikw@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=459265
Committed: https://crrev.com/c29d5c5f8d7ae90012a3d6bd42218b860cb53558
Cr-Commit-Position: refs/heads/master@{#325435}

[johnme, 2015-04-16 13:47:22]

Created Revert of Revert of Disable WebGL conformance test on Win8/NVIDIA

[commit-bot: I haz the power, 2015-04-16 13:47:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1082203004/1

[commit-bot: I haz the power, 2015-04-16 13:48:39]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-16 13:49:20]

Patchset 1 (id:??) landed as
https://crrev.com/c29d5c5f8d7ae90012a3d6bd42218b860cb53558
Cr-Commit-Position: refs/heads/master@{#325435}

[hendrikw, 2015-04-21 23:04:46]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1099203003/ by hendrikw@chromium.org.

The reason for reverting is: The windows test time has been cut in half and
shouldn't time out anymore..