Fix libusb dependecy for Chromium with Android OS.

third_party/libusb/libusb.gyp

 # Copyright (c) 2012 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': {
     'use_system_libusb%': 0,
   },
   'targets': [
     {
@@ skipping 24 matching lines @@
             'src/libusb/descriptor.c',
             'src/libusb/io.c',
             'src/libusb/sync.c',
           ],
           'include_dirs': [
             'src',
             'src/libusb',
             'src/libusb/os',
           ],
           'conditions': [
-            [ 'OS == "linux"', {
+            [ 'OS == "linux" or OS == "android"', {
               'sources': [
                 'src/libusb/os/linux_usbfs.c',
                 'src/libusb/os/threads_posix.c',
               ],
               'defines': [
                 'DEFAULT_VISIBILITY=',
                 'HAVE_POLL_H=1',
                 'HAVE_SYS_TIME_H=1',
                 'OS_LINUX=1',
                 'POLL_NFDS_TYPE=nfds_t',
@@ skipping 28 matching lines @@
                 'THREADS_POSIX=1',
                 '_GNU_SOURCE=1',
               ],
             }],
           ],
         }],
       ],
     },
   ],
 }