Chrome Version       : 50.0.2657.0
Platform : 7956.1.0 (Official Build) dev-channel swanky

What steps will reproduce the problem?
1. Connect to remote BLE device.
2. Disconnect somehow from the UA (i.e. either turn off the remote BLE device or move out of range).
3. Observe that device.addEventListener('gattserverdisconnected', function() { ... }); is not called.

...until: switch tabs in chrome and walah, now the event is fired and our disconnect handler is called.

What is the expected result?
Disconnect event should fire when we lose the link in a reasonable amount of time (doesn't seem to fire at all until a tab is switched). 

What happens instead?
Only fires after switch tabs from our web page doing the BLE comm. 

You can see exactly what I'm doing in code here if necessary (search for gattserverdisconnected): https://github.com/mjdietzx/web-bluetooth-dfu/blob/develop/dist/dfu.js