Read HID report descriptor from sysfs and request permission on connect.

device/hid/hid_service_linux.h

 // Copyright 2014 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_HID_HID_SERVICE_LINUX_H_
 #define DEVICE_HID_HID_SERVICE_LINUX_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "device/hid/device_monitor_linux.h"
 #include "device/hid/hid_device_info.h"
 #include "device/hid/hid_service.h"
 
 struct udev_device;
 
 namespace device {
 
 class HidConnection;
 
 class HidServiceLinux : public HidService,
                         public DeviceMonitorLinux::Observer {
  public:
   HidServiceLinux(scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner);
 
+#if defined(OS_CHROMEOS)
+  virtual void RequestAccess(
+      const HidDeviceId& device_id,
+      const base::Callback<void(bool success)>& callback) override;
+#endif
+
   virtual scoped_refptr<HidConnection> Connect(const HidDeviceId& device_id)
       override;
 
   // Implements DeviceMonitorLinux::Observer:
   virtual void OnDeviceAdded(udev_device* device) override;
   virtual void OnDeviceRemoved(udev_device* device) override;
 
  private:
   virtual ~HidServiceLinux();
 
   void OnRequestAccessComplete(
-      const std::string& path,
-      scoped_ptr<HidDeviceInfo> device_info,
+      const base::Callback<void(bool success)>& callback,
       bool success);
 
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
 
   base::WeakPtrFactory<HidServiceLinux> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HidServiceLinux);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_HID_HID_SERVICE_LINUX_H_