Add testing config for OverlayFullscreenVideo.

Add testing config for OverlayFullscreenVideo.

BUG=642571
Committed: https://crrev.com/99fce27763b037227011e357502b1c700477d153
Cr-Commit-Position: refs/heads/master@{#415825}

[sandersd (OOO until July 31), 2016-08-31 00:29:11]

sandersd@chromium.org changed reviewers:
+ asvitkine@chromium.org

[sandersd (OOO until July 31), 2016-08-31 00:29:11]

This follows after https://codereview.chromium.org/2297973002/, which adds the
feature in question.

[Alexei Svitkine (slow), 2016-08-31 15:46:52]

lgtm

[sandersd (OOO until July 31), 2016-09-01 00:16:04]

The CQ bit was checked by sandersd@chromium.org

[commit-bot: I haz the power, 2016-09-01 00:16:47]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-01 00:59:40]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-01 01:01:45]

Description was changed from

==========
Add testing config for OverlayFullscreenVideo.

BUG=642571
==========

to

==========
Add testing config for OverlayFullscreenVideo.

BUG=642571

Committed: https://crrev.com/99fce27763b037227011e357502b1c700477d153
Cr-Commit-Position: refs/heads/master@{#415825}
==========

[commit-bot: I haz the power, 2016-09-01 01:01:46]

Patchset 1 (id:??) landed as
https://crrev.com/99fce27763b037227011e357502b1c700477d153
Cr-Commit-Position: refs/heads/master@{#415825}

[sandersd (OOO until July 31), 2016-09-02 23:01:22]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/2306233002/ by sandersd@chromium.org.

The reason for reverting is: Turns out we shouldn't do this for optimization
experiments, since we don't actually want this enabled for all dev builds..