Remove the usbPrivate API.

extensions/browser/BUILD.gn

 # 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.
 
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 
 # GYP version: extensions/extensions.gyp:extensions_browser
 source_set("browser") {
   sources = [
@@ skipping 205 matching lines @@
       "api/system_storage/storage_info_provider.cc",
       "api/system_storage/storage_info_provider.h",
       "api/system_storage/system_storage_api.cc",
       "api/system_storage/system_storage_api.h",
       "api/test/test_api.cc",
       "api/test/test_api.h",
       "api/usb/usb_api.cc",
       "api/usb/usb_api.h",
       "api/usb/usb_device_resource.cc",
       "api/usb/usb_device_resource.h",
-      "api/usb_private/usb_private_api.cc",
-      "api/usb_private/usb_private_api.h",
       "api/web_request/form_data_parser.cc",
       "api/web_request/form_data_parser.h",
       "api/web_request/upload_data_presenter.cc",
       "api/web_request/upload_data_presenter.h",
       "api/web_request/web_request_api.cc",
       "api/web_request/web_request_api.h",
       "api/web_request/web_request_api_constants.cc",
       "api/web_request/web_request_api_constants.h",
       "api/web_request/web_request_api_helpers.cc",
       "api/web_request/web_request_api_helpers.h",
@@ skipping 231 matching lines @@
       ]
     }
   }
 
   if (is_win) {
     cflags = [
       "/wd4267", # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     ]
   }
 }