ES31: Add atomic counter buffer support to D3D11 renderer Adds support for atomic counters to the D3D11 renderer using UAV. Bug: angleproject:1729 Test: angle_end2end_tests Change-Id: I2904ba62644685b7d91f7475bd80a81ae414993b Reviewed-on: https://chromium-review.googlesource.com/c/1451259 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>