GitLab

This metric records one bucket when a connection is accepted and another
bucket when a WebRTC upgrade occurs, as a measure of the effectiveness
of WebRTC upgrades. If these buckets have equal counts, this means that
WebRTC upgrades occurred 100% of the time.

However, WebRTC upgrades are not instantaneous; the median upgrade time
is ~5s, and the 95th percentile is 30s. For short-lived connections, we
don't provide enough time for the connection to upgrade, so this
shouldn't really be counted as a "failure" to upgrade.

If a connection disconnects in under 30s, we now log to a new bucket
indicating that the connection disconnected before 30s was up. This will
help us measure a more accurate success rate for WebRTC upgrades.

Bug: 1163779, 1106937
Change-Id: I135820c6541e96818cced0e91719a591ec1510d0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2617304
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#841695}