The naming follows the scheme outlined in bit.ly/v8-gc-stats-collection
and in the UMA document referenced from it.

Bug: chromium:1154636
Change-Id: I872520de06e62f58d771383fd87d8aa06386bf0d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2650213Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72364}