Dashboard - Generate 50'th and 90'th percentiles for metrics
Dashboard - Generate 50'th and 90'th percentiles for metrics

Bug: chromium:883106
Change-Id: Ib92ea8e38962496150b4680ad0054966e80e3ad9
Reviewed-on: https://chromium-review.googlesource.com/1220110
Reviewed-by: Simon Hatch <490a224d89645d3fea983d7189ce51bde0a00c1d@chromium.org>
Reviewed-by: Ben Hayden <d3ffe0e065c2328e497bb32a07f4dcb29138ef5b@chromium.org>
Commit-Queue: Simon Hatch <490a224d89645d3fea983d7189ce51bde0a00c1d@chromium.org>

catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult