Bluetooth: macOS: Adding logs

device/bluetooth/bluetooth_remote_gatt_characteristic_mac.h

Index: device/bluetooth/bluetooth_remote_gatt_characteristic_mac.h
diff --git a/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.h b/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.h
index 4b628c60c97878143a2c522b336690903a74e45a..131d892e23caea7df35204b801fdf3feadf85f2b 100644
--- a/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.h
+++ b/device/bluetooth/bluetooth_remote_gatt_characteristic_mac.h
@@ -104,6 +104,8 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothRemoteGattCharacteristicMac
   // Returns BluetoothRemoteGattDescriptorMac from CBDescriptor.
   BluetoothRemoteGattDescriptorMac* GetBluetoothRemoteGattDescriptorMac(
       CBDescriptor* cb_descriptor) const;
+  // Returns a description for the characteristic, that should be used for logs.
+  std::string ToString() const;
   // Is true if the characteristic has been discovered with all its descriptors.
   bool is_discovery_complete_;
   // gatt_service_ owns instances of this class.