Notify the BluetoothAdapter::Observer when a bluetooth peripheral disconnects on Android and Mac.

device/bluetooth/bluez/bluetooth_adapter_bluez.h

Index: device/bluetooth/bluez/bluetooth_adapter_bluez.h
diff --git a/device/bluetooth/bluez/bluetooth_adapter_bluez.h b/device/bluetooth/bluez/bluetooth_adapter_bluez.h
index 91b88633bb511dece6566f035499d360a0430f73..e8fb572d7ed26b4bfab019c8c2e233eb794f925d 100644
--- a/device/bluetooth/bluez/bluetooth_adapter_bluez.h
+++ b/device/bluetooth/bluez/bluetooth_adapter_bluez.h
@@ -127,10 +127,6 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothAdapterBlueZ
   // BluetoothDevice methods are by address).
   BluetoothDeviceBlueZ* GetDeviceWithPath(const dbus::ObjectPath& object_path);
 
-  // Announces to observers a change in device state that is not reflected by
-  // its D-Bus properties. |device| is owned by the caller and cannot be NULL.
-  void NotifyDeviceChanged(BluetoothDeviceBlueZ* device);
-
   // Announce to observers a device address change.
   void NotifyDeviceAddressChanged(BluetoothDeviceBlueZ* device,
                                   const std::string& old_address);