Vulkan: Begin implementing caps mappings Bug: angleproject:1577 Change-Id: Ibed36dee9120e9182362bc9858cf513f798079cf Reviewed-on: https://chromium-review.googlesource.com/887225 Commit-Queue: Luc Ferron <lucferron@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>