Add support for READ_BUFFER and SAMPLER_BINDING queries BUG=angleproject:1101 TEST=dEQP-GLES3.functional.state_query.integers.* (all pass) Change-Id: I3a70335eeaef39822700ff639443a59849ed53fa Reviewed-on: https://chromium-review.googlesource.com/329866 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>