Add Chromium perf result processing script. We will override this script in a follow-up CL to meet ANGLE's specific needs. Bug: angleproject:6090 Change-Id: I8d3a326645367e90ae79f49ef15ace700d6af106 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3042213 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>