--- services/device/hid/hid_service_fido.h.orig	2022-10-29 17:50:56 UTC
+++ services/device/hid/hid_service_fido.h
@@ -0,0 +1,65 @@
+// Copyright 2014 The Chromium Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SERVICES_DEVICE_HID_HID_SERVICE_LINUX_H_
+#define SERVICES_DEVICE_HID_HID_SERVICE_LINUX_H_
+
+#include <memory>
+
+#include "base/compiler_specific.h"
+#include "base/files/scoped_file.h"
+#include "base/memory/weak_ptr.h"
+#include "base/task/sequenced_task_runner.h"
+#include "build/build_config.h"
+#include "build/chromeos_buildflags.h"
+#include "services/device/hid/hid_device_info.h"
+#include "services/device/hid/hid_service.h"
+
+namespace device {
+
+class HidServiceFido : public HidService {
+ public:
+  HidServiceFido();
+  HidServiceFido(HidServiceFido&) = delete;
+  HidServiceFido& operator=(HidServiceFido&) = delete;
+  ~HidServiceFido() override;
+
+  // HidService:
+  void Connect(const std::string& device_id,
+               bool allow_protected_reports,
+               bool allow_fido_reports,
+               ConnectCallback callback) override;
+  base::WeakPtr<HidService> GetWeakPtr() override;
+
+ private:
+  struct ConnectParams;
+  class BlockingTaskRunnerHelper;
+
+// These functions implement the process of locating, requesting access to and
+// opening a device. Because this operation crosses multiple threads these
+// functions are static and the necessary parameters are passed as a single
+// struct.
+#if BUILDFLAG(IS_CHROMEOS_ASH)
+  static void OnPathOpenComplete(std::unique_ptr<ConnectParams> params,
+                                 base::ScopedFD fd);
+  static void OnPathOpenError(const std::string& device_path,
+                              ConnectCallback callback,
+                              const std::string& error_name,
+                              const std::string& error_message);
+#else
+  static void OpenOnBlockingThread(std::unique_ptr<ConnectParams> params);
+#endif
+  static void FinishOpen(std::unique_ptr<ConnectParams> params);
+
+  const scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
+
+  // |helper_| lives on the sequence |blocking_task_runner_| posts to and holds
+  // a weak reference back to the service that owns it.
+  std::unique_ptr<BlockingTaskRunnerHelper, base::OnTaskRunnerDeleter> helper_;
+  base::WeakPtrFactory<HidServiceFido> weak_factory_{this};
+};
+
+}  // namespace device
+
+#endif  // SERVICES_DEVICE_HID_HID_SERVICE_LINUX_H_