bluetooth: macOS: Remove c-style casting

device/bluetooth/bluetooth_remote_gatt_descriptor_mac.mm

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "device/bluetooth/bluetooth_remote_gatt_descriptor_mac.h"
 
 #include "base/bind.h"
 #import "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 33 matching lines @@
 
 BluetoothRemoteGattDescriptorMac::BluetoothRemoteGattDescriptorMac(
     BluetoothRemoteGattCharacteristicMac* characteristic,
     CBDescriptor* descriptor)
     : gatt_characteristic_(characteristic),
       cb_descriptor_(descriptor, base::scoped_policy::RETAIN),
       value_read_or_write_in_progress_(false) {
   uuid_ = BluetoothAdapterMac::BluetoothUUIDWithCBUUID([cb_descriptor_ UUID]);
   identifier_ = base::SysNSStringToUTF8(
       [NSString stringWithFormat:@"%s-%p", uuid_.canonical_value().c_str(),
-                                 (void*)cb_descriptor_]);
+                                 cb_descriptor_.get()]);
 }
 
 std::string BluetoothRemoteGattDescriptorMac::GetIdentifier() const {
   return identifier_;
 }
 
 BluetoothUUID BluetoothRemoteGattDescriptorMac::GetUUID() const {
   return uuid_;
 }
 
@@ skipping 125 matching lines @@
       static_cast<const BluetoothRemoteGattCharacteristicMac*>(
           descriptor.GetCharacteristic());
   return out << "<BluetoothRemoteGattDescriptorMac "
              << descriptor.GetUUID().canonical_value() << "/" << &descriptor
              << ", characteristic: "
              << characteristic_mac->GetUUID().canonical_value() << "/"
              << characteristic_mac << ">";
 }
 
 }  // namespace device.