John disabled usb resetting recently; its possible that has something to do with it. If that did cause an issue; I would expect to see it manifest as more blacklisted devices thus more purple runs. We'll have to look more into it to confirm one way or another though.
https://codereview.chromium.org/2295603002
While we hash out what to do in the general case, I'm going to put the USB reset behind a flag in device_recovery (rather than disabling it everywhere) and reenable it on chromium.perf.
Second side note. The perf android hosts reboot after each run so enabling usb resetting seems like it would be a noop?
I'm looking into the individual bugs that were filed.
This _may_ be related to crbug.com/619189 which has already been reverted this morning. If thats the case the next bisect attempt should work. Dont know for sure though.
Comment 1 by sullivan@chromium.org
, Sep 7 2016