bluetooth: mac: add connected LE devices to chooser

device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h

Index: device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h
diff --git a/device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h b/device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h
index 20d63a123f92515ebb4a622f85e3e762ba81cf44..9663e1bcad7cfb949efcf3d5a5546b3c834ba365 100644
--- a/device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h
+++ b/device/bluetooth/bluetooth_low_energy_discovery_manager_mac.h
@@ -26,6 +26,7 @@ class BluetoothLowEnergyDiscoveryManagerMac {
   class Observer {
    public:
     // Called when |this| manager has found a device or an update on a device.
+    // |advertisementData| can be nil if the peripheral is already connected.
     virtual void LowEnergyDeviceUpdated(CBPeripheral* peripheral,
                                         NSDictionary* advertisementData,
                                         int rssi) = 0;