Bluetooth: Mac: implementation for start notification

device/bluetooth/bluetooth_remote_gatt_service_mac.h

Index: device/bluetooth/bluetooth_remote_gatt_service_mac.h
diff --git a/device/bluetooth/bluetooth_remote_gatt_service_mac.h b/device/bluetooth/bluetooth_remote_gatt_service_mac.h
index 8b0bd0ea895706c1dea0c5fa5c2173a09da97c4c..ae123d7f424f9a1094ed08bfcde884066afe31f2 100644
--- a/device/bluetooth/bluetooth_remote_gatt_service_mac.h
+++ b/device/bluetooth/bluetooth_remote_gatt_service_mac.h
@@ -60,6 +60,10 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothRemoteGattServiceMac
   // Called by the BluetoothLowEnergyDeviceMac instance when the
   // characteristics value has been written.
   void DidWriteValue(CBCharacteristic* characteristic, NSError* error);
+  // Called by the BluetoothLowEnergyDeviceMac instance when the notify session
+  // has been started or failed.
+  void DidUpdateNotificationState(CBCharacteristic* characteristic,
+                                  NSError* error);
   // Returns true if the characteristics has been discovered.
   bool IsDiscoveryComplete();