Add gl_DrawID emulation for ESSL3 with ANGLE_multi_draw Bug: chromium:890539 Change-Id: I3d9a9429608afb454f076013f3ed844e115c56cc Reviewed-on: https://chromium-review.googlesource.com/c/1368784 Reviewed-by: Kai Ninomiya <kainino@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Austin Eng <enga@chromium.org>