OpenGL 4.2 is required when using ARB_compute_shader extension BUG=angleproject:1702 TESTCASE=angle_end2end_tests Change-Id: I45fe21bc14310b9c873e83004a8ac8766865fbb9 Reviewed-on: https://chromium-review.googlesource.com/428690 Reviewed-by: Yunchao He <yunchao.he@intel.com> Reviewed-by: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Corentin Wallez <cwallez@chromium.org>