Remove the usbPrivate API.

extensions/extensions.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': [
     {
@@ skipping 477 matching lines @@
         'browser/api/system_storage/storage_info_provider.cc',
         'browser/api/system_storage/storage_info_provider.h',
         'browser/api/system_storage/system_storage_api.cc',
         'browser/api/system_storage/system_storage_api.h',
         'browser/api/test/test_api.cc',
         'browser/api/test/test_api.h',
         'browser/api/usb/usb_api.cc',
         'browser/api/usb/usb_api.h',
         'browser/api/usb/usb_device_resource.cc',
         'browser/api/usb/usb_device_resource.h',
-        'browser/api/usb_private/usb_private_api.cc',
-        'browser/api/usb_private/usb_private_api.h',
         'browser/api/web_request/form_data_parser.cc',
         'browser/api/web_request/form_data_parser.h',
         'browser/api/web_request/upload_data_presenter.cc',
         'browser/api/web_request/upload_data_presenter.h',
         'browser/api/web_request/web_request_api.cc',
         'browser/api/web_request/web_request_api.h',
         'browser/api/web_request/web_request_api_constants.cc',
         'browser/api/web_request/web_request_api_constants.h',
         'browser/api/web_request/web_request_api_helpers.cc',
         'browser/api/web_request/web_request_api_helpers.h',
@@ skipping 664 matching lines @@
       'conditions': [
         ['OS=="win" and win_use_allocator_shim==1', {
           'dependencies': [
             '../base/allocator/allocator.gyp:allocator',
           ],
         }],
       ],
     },
   ]
 }