device: Cleanup class/struct forward declarations

device/usb/usb_device_impl.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 <list>
@@ skipping 12 matching lines @@
 
 struct libusb_device;
 struct libusb_device_descriptor;
 struct libusb_device_handle;
 struct libusb_config_descriptor;
 
 namespace base {
 class SequencedTaskRunner;
 }
 
-namespace dbus {
-class FileDescriptor;
-}
-
 namespace device {
 
 class UsbDeviceHandleImpl;
 class UsbContext;
 
 typedef struct libusb_device* PlatformUsbDevice;
 typedef struct libusb_config_descriptor* PlatformUsbConfigDescriptor;
 typedef struct libusb_device_handle* PlatformUsbDeviceHandle;
 
 class UsbDeviceImpl : public UsbDevice {
@@ skipping 54 matching lines @@
 
   scoped_refptr<base::SequencedTaskRunner> task_runner_;
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(UsbDeviceImpl);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_USB_USB_DEVICE_IMPL_H_