Don't issue any extra geometry for the IOSurface leak workaround

Don't issue any extra geometry for the IOSurface leak workaround

The official solution to the problem where an IOSurface outlives
its bindings is to send a glBegin/glEnd pair down, which will
kick loose any references in the kernel.

BUG=158469
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=170938

[ccameron, 2012-12-04 03:55:36]

I got into contact with Apple about this after I verified the issue still
existed on 10.8.

This is a known issue, and the official workaround is to issue a glBegin/glEnd
pair with no geometry.  I hadn't tried doing a no-geometry call (I'd assumed
that it would be optimized out), but it does the trick.

I need to add automation tests for this soon.

[Nico, 2012-12-04 04:23:44]

lgtm!

Thanks for following through on this. Please provide a small summary of the
recommended workaround (something like "the driver doesn't have enough data for
surface flushing until glBegin/glEnd is run, the official workaround is just
call that" in whole sentence form is enough) on the bug.

[Ken Russell (switch to Gerrit), 2012-12-04 04:35:55]

LGTM! Excellent work diagnosing this problem and rediscovering the necessary
workaround.

[commit-bot: I haz the power, 2012-12-04 09:38:44]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/ccameron@chromium.org/11418303/1

[commit-bot: I haz the power, 2012-12-04 12:08:02]

Change committed as 170938