Chrome Version       : 52.0.2743.116
OS Version: 8350.68.0

I'm using a Thinkpad Compact Bluetooth Keyboard with Trackpoint. It's been connected successfully to the Pixel for several weeks without issue. Then I returned from travel for 3 weeks and every day the bluetooth stack crashes and completely disappears from the UI. 

Before: https://screenshot.googleplex.com/UwesJ6Wn0M6 (and https://screenshot.googleplex.com/vt4My5ahC3d)
After: https://screenshot.googleplex.com/KiaAeMJW1FJ


What steps will reproduce the problem?
I'm not able to proactively reproduce, but it occurs daily since Monday. The keyboard is charged and working normally when Bluetooth is available on the chromebook. 

There are two occurrences:
1. The keyboard temporarily looses connectivity for about 10 seconds. The BT settings are still available and the keyboard reconnects.
2. The keyboard looses connectivity permanently and all Bluetooth settings in the Chrome OS UI disappear.Restarting the chromebook resolves the issue. 

I'm not aware of a way to restart or reinitiate the bluetooth stack.

What is the expected result?
Uninterrupted BT connection.

What happens instead of that?
Lose input control of the device and cannot recover without restarting.

Please provide any additional information below. Attach a screenshot if
possible.

UserAgentString: Mozilla/5.0 (X11; CrOS x86_64 8350.68.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36