Perf Tests: Update histogram units. Use "ms_smallerIsBetter" instead of "msBestFitFormat". This matches the requirements of the online docs as well as ensuring the dashboard knows which way to track the regressions. https://chromium.googlesource.com/catapult/+/HEAD/docs/histogram-set-json-format.md Bug: angleproject:6090 Change-Id: I0b234725b55d4abb1dd1e8153e132fdbcbad1c60 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3115225 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Cody Northrop <cnorthrop@google.com> Reviewed-by: Tim Van Patten <timvp@google.com>