Use udev for serial device enumeration on Linux

device/serial/serial.gyp

+# 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.
+
+{
+  'variables': {
+    'chromium_code': 1,
+  },
+  'targets': [
+    {
+      'target_name': 'device_serial',
+      'type': 'static_library',
+      'include_dirs': [
+        '../..',
+      ],
+      'conditions': [
+        ['OS=="linux"', {
+          'dependencies': [
+            '../../build/linux/system.gyp:udev',
+          ],
+        }],
+      ],
+      'sources': [
+        'serial_device_enumerator.cc',
+        'serial_device_enumerator.h',
+        'serial_device_enumerator_linux.cc',
+        'serial_device_enumerator_linux.h',
+        'serial_device_enumerator_mac.cc',
+        'serial_device_enumerator_mac.h',
+        'serial_device_enumerator_win.cc',
+        'serial_device_enumerator_win.h',
+        'serial_device_info.cc',
+        'serial_device_info.h',
+      ],
+    },
+  ],
+}