Custom metric: Fix Desktop UI benchmark failure
Custom metric: Fix Desktop UI benchmark failure

This CL fixes some benchmark story failures on the waterfall for
Destkop UI benchmark.

Bug: chromium:1239010
Change-Id: Iac177cd3bad27f7c0e2338de24ad7155d17813d2
Reviewed-on: https://chromium-review.googlesource.com/c/catapult/+/3101938
Reviewed-by: Deep Roy <196de8ecef43ff77ba1a773ccd52374e3849c302@chromium.org>
Commit-Queue: Yuheng Huang <1a14baf591cdc75e4cdda74a9c65c529d9a49175@chromium.org>

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