Bluetooth: macOS: Implementing read/write for descriptors

device/bluetooth/bluetooth_low_energy_device_mac.h

Index: device/bluetooth/bluetooth_low_energy_device_mac.h
diff --git a/device/bluetooth/bluetooth_low_energy_device_mac.h b/device/bluetooth/bluetooth_low_energy_device_mac.h
index 0b1aafd2b4f209fb962ebbed73229449047682c0..e2823d16eded4be599c5ab404dc5cc1d93a166ba 100644
--- a/device/bluetooth/bluetooth_low_energy_device_mac.h
+++ b/device/bluetooth/bluetooth_low_energy_device_mac.h
@@ -28,6 +28,7 @@ namespace device {
 
 class BluetoothAdapterMac;
 class BluetoothRemoteGattServiceMac;
+class BluetoothRemoteGattDescriptorMac;
 
 class DEVICE_BLUETOOTH_EXPORT BluetoothLowEnergyDeviceMac
     : public BluetoothDeviceMac {
@@ -90,6 +91,8 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothLowEnergyDeviceMac
   void DidUpdateNotificationState(CBCharacteristic* characteristic,
                                   NSError* error);
   void DidDiscoverDescriptors(CBCharacteristic* characteristic, NSError* error);
+  void DidUpdateValueForDescriptor(CBDescriptor* cb_descriptor, NSError* error);
+  void DidWriteValueForDescriptor(CBDescriptor* descriptor, NSError* error);
 
   static std::string GetPeripheralIdentifier(CBPeripheral* peripheral);
 
@@ -123,6 +126,10 @@ class DEVICE_BLUETOOTH_EXPORT BluetoothLowEnergyDeviceMac
   BluetoothRemoteGattServiceMac* GetBluetoothRemoteGattService(
       CBService* service) const;
 
+  // Returns BluetoothRemoteGattDescriptorMac based on the CBDescriptor.
+  BluetoothRemoteGattDescriptorMac* GetBluetoothRemoteGattDescriptor(
+      CBDescriptor* cb_descriptor) const;
+
   // Callback used when the CoreBluetooth Peripheral is disconnected.
   void DidDisconnectPeripheral(NSError* error);