Test it against multiple versions of the OpenGL renderer so make sure that
both core and compatibility profile are tested.
Fixes:
* conformance/rendering/point-size.html
* conformance/rendering/point-with-gl-pointcoord-in-fragment-shader.html
* PointSpritesTest
* particle_system sample
BUG=angleproject:883
Change-Id: Ib7625cb12faeac21016a9ff551aa650ba24e789f
Reviewed-on: https://chromium-review.googlesource.com/277692Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>
