Make udev target disappear on linux when use_udev==0

device/device_tests.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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 65 matching lines @@
                 '../base/allocator/allocator.gyp:allocator',
               ],
             }],
           ],
         }],
         ['OS=="linux" and use_udev==0', {
           # Udev is the only Linux implementation. If we're compiling without
           # Udev, disable these unittests.
           'dependencies!': [
             'hid/hid.gyp:device_hid',
+            'serial/serial.gyp:device_serial',
+            'serial/serial.gyp:device_serial_test_util',
           ],
           'sources/': [
+            ['exclude', '^serial/'],
             ['exclude', '^hid/'],
           ],
         }],
       ],
     },
   ],
 }