Add a histogram for source VideoFrame formats uploaded to viz.

Will help us estimate impact of changes and issues which affect
only a single format in the future. Expiry set for one year, we
can remove it if it proves not useful then.

R=evliu

Bug: 370303497
Change-Id: I02e77911e1f540d4b40f486499ae777cfd6e29c6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5902290
Auto-Submit: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Evan Liu <evliu@google.com>
Commit-Queue: Evan Liu <evliu@google.com>
Cr-Commit-Position: refs/heads/main@{#1362722}