This script was not parsing the trace list properly and was
running no tests.

Bug: angleproject:5811
Change-Id: I925bc16ac476823ca2f850d4a9e208b9bb5deb62
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2810805Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>