I saw that you already filed  issue 772539 . Is it necessary to also add metrics for how long settings/quick settings are open in addition? I'm not sure what value the settings metric provides if we already have the number of scans.

Discussed this offline. It seems that "time scanning" is an important metric since it give us some indication of how much time users are spending during scans. Thus, I would instead propose that we add metrics for how long scans are active instead of how long settings or quick settings are open.

Taking this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fb813a421a3821c32b2d95ac32cfce3752cab6b4

commit fb813a421a3821c32b2d95ac32cfce3752cab6b4
Author: Kyle Horimoto <khorimoto@google.com>
Date: Wed Oct 11 19:21:54 2017

[CrOS Tether] Add a metric for the length of a host scan batch.

Here, a batch refers to one or more host scans in close succession. This
metric will provide us with a way to quantify how much users are
scanning, which will be helpful in determining Bluetooth stability.

Bug:  772536 , 672263
Change-Id: I33f97bdca7a25b5f0a66c1e89be28718176a2d40
Reviewed-on: https://chromium-review.googlesource.com/711097
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Ryan Hansberry <hansberry@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#508059}
[modify] https://crrev.com/fb813a421a3821c32b2d95ac32cfce3752cab6b4/chromeos/components/tether/host_scan_scheduler.cc
[modify] https://crrev.com/fb813a421a3821c32b2d95ac32cfce3752cab6b4/chromeos/components/tether/host_scan_scheduler.h
[modify] https://crrev.com/fb813a421a3821c32b2d95ac32cfce3752cab6b4/chromeos/components/tether/host_scan_scheduler_unittest.cc
[modify] https://crrev.com/fb813a421a3821c32b2d95ac32cfce3752cab6b4/tools/metrics/histograms/histograms.xml

We've decided to delay this until M-63 since there is risk in merging it to M-62 this late in the game.