Bluetooth: mac: Working on macOS descriptor implementation.

device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm

Index: device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm
diff --git a/device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm b/device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm
index d4914adc3fad87676f90e15ff686cab0448fd920..4f8a1b853928ee53d48ad465865045002c99f75d 100644
--- a/device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm
+++ b/device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm
@@ -44,6 +44,11 @@ class BluetoothLowEnergyPeripheralBridge {
     device_mac_->DidUpdateNotificationState(characteristic, error);
   }
 
+  void DidDiscoverDescriptors(CBCharacteristic* characteristic,
+                              NSError* error) {
+    device_mac_->DidDiscoverDescriptors(characteristic, error);
+  }
+
   CBPeripheral* GetPeripheral() { return device_mac_->GetPeripheral(); }
 
  private:
@@ -101,4 +106,11 @@ class BluetoothLowEnergyPeripheralBridge {
                                           error:(nullable NSError*)error {
   bridge_->DidUpdateNotificationState(characteristic, error);
 }
+
+- (void)peripheral:(CBPeripheral*)peripheral
+    didDiscoverDescriptorsForCharacteristic:(CBCharacteristic*)characteristic
+                                      error:(nullable NSError*)error {
+  bridge_->DidDiscoverDescriptors(characteristic, error);
+}
+
 @end