[web-bluetooth] Add an event when a device is disconnected.

jyasskin has just created a new issue for 
https://github.com/WebBluetoothCG/web-bluetooth:

== Add an event when a device is disconnected. ==
If a device goes out of range, we should let applications know.

See https://github.com/WebBluetoothCG/web-bluetooth/issues/159

Received on Wednesday, 9 September 2015 20:28:44 UTC