Add JankTracking REF.

Bug: 847581
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: If37be17ab484884b4aaef83b1ddc2735a5d17aa0
Reviewed-on: https://chromium-review.googlesource.com/1077009
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Steve Kobes <skobes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562647}
2 files changed