[Ozone] Allow surfaceless path to have 2 frames pending

[Ozone] Allow surfaceless path to have 2 frames pending

Allows the surfaceless path (used for Ozone/Freon) to queue up more
work while waiting for the currently displayed buffer to be released
by the hardware. In turn this means slightly better frame rates on
WebGL apps as we're able to better hit the vsync deadline.

BUG=467135
TESTS=Ran on stout with Freon and verified that the FPS on aquarium increased to similar values as X11

Committed: https://crrev.com/9df811e63e97ca7c079a0eb13ad8814716ad123d
Cr-Commit-Position: refs/heads/master@{#322634}

[dnicoara, 2015-03-27 17:40:00]

dnicoara@chromium.org changed reviewers:
+ brianderson@chromium.org, danakj@chromium.org

[dnicoara, 2015-03-27 17:40:00]

danakj@ for OWNERS review
brianderson@ FYI

[danakj, 2015-03-27 17:40:53]

LGTM % brianderson

[brianderson, 2015-03-27 18:53:37]

lgtm

[dnicoara, 2015-03-27 20:00:13]

The CQ bit was checked by dnicoara@chromium.org

[commit-bot: I haz the power, 2015-03-27 20:00:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1038263002/1

[commit-bot: I haz the power, 2015-03-27 20:30:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-27 20:31:21]

Patchset 1 (id:??) landed as
https://crrev.com/9df811e63e97ca7c079a0eb13ad8814716ad123d
Cr-Commit-Position: refs/heads/master@{#322634}