Move device/usb classes from the FILE thread to UI thread.

device/usb/usb.gyp

 # Copyright 2013 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
       'target_name': 'device_usb',
       'type': 'static_library',
       'dependencies': [
         '../../components/components.gyp:device_event_log_component',
         '../../net/net.gyp:net',
         '../../third_party/libusb/libusb.gyp:libusb',
       ],
       'include_dirs': [
         '../..',
       ],
       'sources': [
         'usb_context.cc',
         'usb_context.h',
         'usb_descriptors.cc',
         'usb_descriptors.h',
         'usb_device_impl.cc',
         'usb_device_impl.h',
+        'usb_device.cc',
         'usb_device.h',
         'usb_device_filter.cc',
         'usb_device_filter.h',
         'usb_device_handle_impl.cc',
         'usb_device_handle_impl.h',
         'usb_device_handle.h',
         'usb_error.cc',
         'usb_error.h',
         'usb_ids.cc',
         'usb_ids.h',
@@ skipping 33 matching lines @@
         }],
         ['chromeos==1', {
           'dependencies': [
             '../../chromeos/chromeos.gyp:chromeos',
           ],
         }],
       ]
     },
   ],
 }