Google Chrome	53.0.2773.0 (Official Build) dev (64-bit)
Platform	8481.0.0 (Official Build) dev-channel link

What steps will reproduce the problem?
(1) Make sure a nearby BLE device has just the "BR/EDR Not Supported" flag set, not any of the "discoverable" flags.
(2) Go to https://googlechrome.github.io/samples/web-bluetooth/automatic-reconnect.html
(3) Click "Scan" button, Bluetooth choose shows up

What is the expected output?
The nearby BLE device should show up.

What do you see instead?
It doesn't.

BlueZ now makes filtered discovery able to detect beacons with http://git.kernel.org/cgit/bluetooth/bluez.git/commit/?id=1ca09244f3d9f755fcec81325f6f1d96d1498674

This means Chromium has to trigger a filtered discovery to see them. Passing an empty UUIDs dictionnary will also trigger it by the way so if we only scan by device name or device name prefix, we should use that trick.

We'll also have to cherry-pick this BlueZ patch.

Background thread: https://github.com/WebBluetoothCG/web-bluetooth/issues/141