Bluetooth: macOS: Making code to get mac descriptors more coherent

device/bluetooth/bluetooth_remote_gatt_service_mac.mm

 // Copyright 2016 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_service_mac.h"
 
 #import <CoreBluetooth/CoreBluetooth.h>
 #include <vector>
 
 #include "base/logging.h"
@@ skipping 174 matching lines @@
 CBPeripheral* BluetoothRemoteGattServiceMac::GetCBPeripheral() const {
   return bluetooth_device_mac_->GetPeripheral();
 }
 
 CBService* BluetoothRemoteGattServiceMac::GetService() const {
   return service_;
 }
 
 BluetoothRemoteGattCharacteristicMac*
 BluetoothRemoteGattServiceMac::GetBluetoothRemoteGattCharacteristicMac(
-    CBCharacteristic* characteristic) const {
+    CBCharacteristic* cb_characteristic) const {
   auto found = std::find_if(
       gatt_characteristic_macs_.begin(), gatt_characteristic_macs_.end(),
-      [characteristic](
+      [cb_characteristic](
           const std::pair<
               const std::string,
               std::unique_ptr<BluetoothRemoteGattCharacteristicMac>>& pair) {
-        return pair.second->GetCBCharacteristic() == characteristic;
+        return pair.second->GetCBCharacteristic() == cb_characteristic;
       });
   if (found == gatt_characteristic_macs_.end()) {
     return nullptr;
   } else {
     return found->second.get();
   }
 }
 
+BluetoothRemoteGattDescriptorMac*
+BluetoothRemoteGattServiceMac::GetBluetoothRemoteGattDescriptorMac(
+    CBDescriptor* cb_descriptor) const {
+  CBCharacteristic* cb_characteristic = [cb_descriptor characteristic];
+  BluetoothRemoteGattCharacteristicMac* gatt_characteristic_mac =
+      GetBluetoothRemoteGattCharacteristicMac(cb_characteristic);
+  if (!gatt_characteristic_mac) {
+    return nullptr;
+  }
+  return gatt_characteristic_mac->GetBluetoothRemoteGattDescriptorMac(
+      cb_descriptor);
+}
+
 DEVICE_BLUETOOTH_EXPORT std::ostream& operator<<(
     std::ostream& out,
     const BluetoothRemoteGattServiceMac& service) {
   const BluetoothLowEnergyDeviceMac* bluetooth_device_mac_ =
       static_cast<const BluetoothLowEnergyDeviceMac*>(service.GetDevice());
   return out << "<BluetoothRemoteGattServiceMac "
              << service.GetUUID().canonical_value() << "/" << &service
              << ", device: " << bluetooth_device_mac_->GetAddress() << "/"
              << bluetooth_device_mac_ << ">";
 }
 
 }  // namespace device