Vulkan: Merge CommandQueue and TaskProcessor. Bug: b/172704839 Change-Id: I43a40e6a3e1eb00a7ddebfba6e915437aa69aeb6 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2525141 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>