Bluetooth: Mac: implementation for start notification

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 ac7b66ea44ce11aca7113192c5ea4e6d08cd205a..d4914adc3fad87676f90e15ff686cab0448fd920 100644
--- a/device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm
+++ b/device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm
@@ -39,6 +39,11 @@ class BluetoothLowEnergyPeripheralBridge {
     device_mac_->DidWriteValue(characteristic, error);
   }
 
+  void DidUpdateNotificationState(CBCharacteristic* characteristic,
+                                  NSError* error) {
+    device_mac_->DidUpdateNotificationState(characteristic, error);
+  }
+
   CBPeripheral* GetPeripheral() { return device_mac_->GetPeripheral(); }
 
  private:
@@ -89,4 +94,11 @@ class BluetoothLowEnergyPeripheralBridge {
                              error:(nullable NSError*)error {
   bridge_->DidWriteValue(characteristic, error);
 }
+
+- (void)peripheral:(CBPeripheral*)peripheral
+    didUpdateNotificationStateForCharacteristic:
+        (nonnull CBCharacteristic*)characteristic
+                                          error:(nullable NSError*)error {
+  bridge_->DidUpdateNotificationState(characteristic, error);
+}
 @end