We can get by with only including these in libANGLE, since libGLESv2
pulls in libANGLE.

BUG=angle:773

Change-Id: Iccbdb968b3c55528e2a7e1dd55f4f1280a70bfe9
Reviewed-on: https://chromium-review.googlesource.com/232967Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>