Enable FilePathWatcher base unittests on Android.

base/BUILD.gn

 # Copyright (c) 2013 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/ui.gni")
 import("//testing/test.gni")
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
@@ skipping 1356 matching lines @@
   if (is_posix || is_ios) {
     sources += [ "message_loop/message_pump_libevent_unittest.cc" ]
     deps += [ "//third_party/libevent" ]
   }
 
   if (is_android) {
     deps += [ "//testing/android/native_test:native_test_native_code" ]
     set_sources_assignment_filter([])
     sources += [ "debug/proc_maps_linux_unittest.cc" ]
     set_sources_assignment_filter(sources_assignment_filter)
-    sources -= [ "files/file_path_watcher_unittest.cc" ]
   }
 
   # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 }
 
 if (is_android) {
   # GYP: //base.gyp:base_jni_headers
   generate_jni("base_jni_headers") {
     sources = [
@@ skipping 91 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }