[discardable] Extend histograms.

Change-Id: Ic1dafa3db74f7dfb756beeaf1949cc4e83aef802
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3148411


Reviewed-by: Thiabaud Engelbrecht <thiabaud@google.com>
Commit-Queue: Benoit L <lizeb@chromium.org>
Cr-Commit-Position: refs/heads/main@{#919283}