use_udev is more accurate than is_linux for udev gn deps

device/serial/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("//third_party/mojo/src/mojo/public/tools/bindings/mojom.gni")
 
 # GYP version: device/serial/serial.gyp:device_serial
 static_library("serial") {
   output_name = "device_serial"
 
@@ skipping 31 matching lines @@
   ]
 
   public_deps = [
     ":serial_mojo",
     "//base",
   ]
   deps = [
     "//third_party/mojo/src/mojo/public/cpp/system",
   ]
 
-  if (is_linux) {
+  if (use_udev) {

[tfarina, 2015/08/18 20:09:19]

OK.

https://chromium.googlesource.com/chromium/src/+/master/device/serial/serial....

     deps += [ "//device/udev_linux" ]
   }
   if (is_chromeos) {
     deps += [ "//chromeos" ]
   }
 }
 
 # GYP version: device/serial/serial.gyp:device_serial_test_util
 static_library("test_support") {
   sources = [
@@ skipping 13 matching lines @@
     "//extensions:extensions_renderer_resources_grit",
   ]
 
   sources = [
     "data_stream.mojom",
     "data_stream_serialization.mojom",
     "serial.mojom",
     "serial_serialization.mojom",
   ]
 }