GitLab

This change adds comments to make it clear which functions are used for
reporting metrics and moves them to the bottom of the class.

Bug: chromium:757625
Change-Id: I07f82bb50df9ac77afc4d235d802c576aa326bbc
Reviewed-on: https://chromium-review.googlesource.com/1102088Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570131}