device: Cleanup class/struct forward declarations

device/usb/usb_device_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_USB_USB_DEVICE_IMPL_H_
 #define DEVICE_USB_USB_DEVICE_IMPL_H_
 
 #include <stdint.h>
 
 #include <string>
 #include <utility>
 
 #include "base/files/scoped_file.h"
 #include "base/macros.h"
 #include "base/threading/thread_checker.h"
 #include "build/build_config.h"
 #include "device/usb/usb_device.h"
 #include "device/usb/webusb_descriptors.h"
 
 namespace base {
 class SequencedTaskRunner;
 }
 
 namespace device {
 
-struct UsbConfigDescriptor;
 struct UsbDeviceDescriptor;
 
 class UsbDeviceLinux : public UsbDevice {
  public:
 // UsbDevice implementation:
 #if defined(OS_CHROMEOS)
   void CheckUsbAccess(const ResultCallback& callback) override;
 #endif  // OS_CHROMEOS
   void Open(const OpenCallback& callback) override;
 
@@ skipping 38 matching lines @@
 
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbDeviceLinux);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_USB_USB_DEVICE_IMPL_H_