Read characteristic implementation on macOS

device/bluetooth/bluetooth_device_mac.h

 // Copyright 2015 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.
 
 #ifndef DEVICE_BLUETOOTH_BLUETOOTH_DEVICE_MAC_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_DEVICE_MAC_H_
 
 #include "base/macros.h"
 #include "device/bluetooth/bluetooth_device.h"
+#include "device/bluetooth/bluetooth_gatt_service.h"
 
 @class NSDate;
 
 namespace device {
 
 class BluetoothAdapterMac;
 
 class DEVICE_BLUETOOTH_EXPORT BluetoothDeviceMac : public BluetoothDevice {
  public:
   ~BluetoothDeviceMac() override;
 
   // Returns the time of the most recent interaction with the device.  Returns
   // nil if the device has never been seen.
   virtual NSDate* GetLastUpdateTime() const = 0;
 
   // Converts between ConnectErrorCode and NSError.
   static NSError* GetNSErrorFromConnectErrorCode(
       BluetoothDevice::ConnectErrorCode error_code);
   static BluetoothDevice::ConnectErrorCode GetConnectErrorCodeFromNSError(
       NSError* error);
+  static NSError* GetNSErrorFromGattErrorCode(
+      BluetoothGattService::GattErrorCode error_code);
+  static BluetoothGattService::GattErrorCode GetGattErrorCodeFromNSError(
+      NSError* error);
 
  protected:
   BluetoothDeviceMac(BluetoothAdapterMac* adapter);
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothDeviceMac);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_DEVICE_MAC_H_