Note that this splits off counters added in
https://chromium-review.googlesource.com/c/v8/v8/+/1186343

R=ahaas@chromium.org

Bug: chromium:868844
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I263c63a51d8ce3418eacabb6beb11fa1b3dfaa96
Reviewed-on: https://chromium-review.googlesource.com/1186721Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55357}