CRAS: server_metrics - Log number of underruns
When we remove device, metrics will log number of underrruns
of it to UMA. It can help us to know how often the users get
underrun.
Besides, this change also let longest_fetch_delay be logged
correctly. It was unavailable because we didn't have permission
to access /var/lib/metrics.
BUG=b:77485214
TEST=Manually trigger underrun and it can be recorded well.
Change-Id: Ic9740d3bef935da76133e537b631fa63b8e2c74c
Reviewed-on: https://chromium-review.googlesource.com/1148178
Commit-Ready: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Tested-by: Yu-Hsuan Hsu <yuhsuan@chromium.org>
Reviewed-by: Cheng-Yi Chiang <cychiang@chromium.org>
9 files changed
