Gives us better performance when using the command graph. Performance
regressed significantly in "Vulkan: Track resource usage via counter."

Perf test scores:
before CL: 1060
after CL: 1245
this CL: 1085

The small remaining regression can be investigated more fully in the
future. It's possible there is some small acceptable regression when
switching the command graph design for multithreading.

Test: angle_perftests (DrawCall*vulkan_null*manyvbos*)
Bug: angleproject:2464
Change-Id: I5e625999a8e8b3e1a045908c51e549f472cd4209
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1817102Reviewed-by: Tim Van Patten <timvp@google.com>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>