Read characteristic implementation on macOS

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 19b628b720296e50b0e0564b030b321fa55ab39b..24d9d879aef099a15c9b8ba0e9215439272b3977 100644
--- a/device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm
+++ b/device/bluetooth/bluetooth_low_energy_peripheral_delegate.mm
@@ -31,6 +31,10 @@ class BluetoothLowEnergyPeripheralBridge {
     device_mac_->DidDiscoverCharacteristics(service, error);
   };
 
+  void DidUpdateValue(CBCharacteristic* characteristic, NSError* error) {
+    device_mac_->DidUpdateValue(characteristic, error);
+  }
+
   CBPeripheral* GetPeripheral() { return device_mac_->GetPeripheral(); }
 
  private:
@@ -70,4 +74,10 @@ class BluetoothLowEnergyPeripheralBridge {
   bridge_->DidDiscoverCharacteristics(service, error);
 }
 
+- (void)peripheral:(CBPeripheral*)peripheral
+    didUpdateValueForCharacteristic:(CBCharacteristic*)characteristic
+                              error:(NSError*)error {
+  bridge_->DidUpdateValue(characteristic, error);
+}
+
 @end