Performance sheriffs: This CL adds better accounting and can thus cause
regressions.

Also-By: cbruni@chromium.org
Bug: 
Change-Id: I38cdb702af201033e180741af40c4c5915553798
Reviewed-on: https://chromium-review.googlesource.com/623867Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47476}