Add callbacks to register EGL bindings from Ozone

Add callbacks to register EGL bindings from Ozone

Ozone needs to provide a custom way to load EGL and GLES2 bindings. Since Ozone
lives in ui/gfx/ozone it cannot have dependencies to ui/gl to register the
libraries.

This patch adds to callbacks to Ozone's LoadEGLGLES2Bindings function such that
when performing GL bindings initialization ui/gl will provide the callbacks to
register the bindings.

BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=231893

[rjkroege, 2013-10-29 16:02:42]

lgtm

Proviso: this is a bit un-nice. If this is the only case that needs this
property, then I think that the disruption and complexity of the alternatives
outweigh the un-niceness here.

If however we discover ourselves needing to do any more of this, we probably
will want to revisit this.

[kalyank, 2013-10-29 16:14:15]

On 2013/10/29 16:02:42, rjkroege wrote:
> lgtm
> 
> Proviso: this is a bit un-nice. If this is the only case that needs this
> property, then I think that the disruption and complexity of the alternatives
> outweigh the un-niceness here.
> 
> If however we discover ourselves needing to do any more of this, we probably
> will want to revisit this.

Ya, agree.

[dnicoara, 2013-10-29 18:36:06]

Adding piman@ for ui/gl owners.

[piman, 2013-10-29 20:52:22]

LGTM, though I feel an interface rather than 2 callbacks would be nicer.

[dnicoara, 2013-10-29 21:23:31]

On 2013/10/29 20:52:22, piman wrote:
> LGTM, though I feel an interface rather than 2 callbacks would be nicer.

Thanks. I was on the fence on this as well, but talking with rjkroege@ and
sadrul@, the consensus is that the interface is unlikely to change and (as
rjkroege@ said) the number of callbacks is small enough that the complexity of
alternatives outweigh the ugliness in this case.

I'll definitely keep this in mind if we ever want to change it again.

[commit-bot: I haz the power, 2013-10-30 12:35:22]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dnicoara@chromium.org/47213009/1

[commit-bot: I haz the power, 2013-10-30 15:27:39]

Retried try job too often on win7_aura for step(s) browser_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win7_aura&...

[commit-bot: I haz the power, 2013-10-30 15:33:33]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dnicoara@chromium.org/47213009/1

[commit-bot: I haz the power, 2013-10-30 19:23:33]

Change committed as 231893