Merge components/usb_service into device/usb.

device/usb/usb_error.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 COMPONENTS_USB_SERVICE_USB_ERROR_H_
-#define COMPONENTS_USB_SERVICE_USB_ERROR_H_
+#ifndef DEVICE_USB_USB_ERROR_H_
+#define DEVICE_USB_USB_ERROR_H_
 
 #include <string>
 
-namespace usb_service {
+namespace device {
 
 // A number of libusb functions which return a member of enum libusb_error
 // return an int instead so for convenience this function takes an int.
-std::string ConvertErrorToString(int errcode);
+std::string ConvertPlatformUsbErrorToString(int errcode);
 
-}  // namespace usb_service;
+}  // namespace device
 
-#endif  // COMPONENTS_USB_SERVICE_USB_ERROR_H_
+#endif  // DEVICE_USB_USB_ERROR_H_