Adds several new command line arguments and documents all args in the README. Changes the trace tests to output milliseconds. Bug: b/169600938 Change-Id: Ie8c7840a6a8958951992c806979dde6dc7d8a709 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2438194 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com> Reviewed-by: Cody Northrop <cnorthrop@google.com>
