[Glamor] Configuration for DRI3 support preview

[davyaxel at free.fr]

On 12/12/2013, Michel Dänzer wrote :
> On Mit, 2013-12-11 at 22:22 +0100, davyaxel at free.fr wrote:
>>
>> libgbm can be present but link to other drivers that Mesa, and then in
>> this situation we don't know in what EGLNativePixmapType will result.
>
> That sounds like something that would need to be handled at runtime, not
> build time.
>
>
Well, when I meant 'linked', I was more thinking 'associated'.
For example: http://git.ti.com/glsdk/libgbm/trees/master allows
any gl driver to implement gbm.
I expect that at compilation time we get the right headers,
and then we would have tested correctly what is EGLNativePixmapType.