Create a new GN target //services/service_junit_tests, and enable it in bots.

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.
 
 # This is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 246 matching lines @@
       "//base/android/linker:chromium_android_linker",
       "//build/android/gyp/test:hello_world",
       "//chrome/android/webapk/shell_apk:webapk",
       "//components/invalidation/impl:components_invalidation_impl_junit_tests",
       "//components/policy/android:components_policy_junit_tests",
       "//content/public/android:content_junit_tests",
       "//content/shell/android:content_shell_apk",
       "//device:device_junit_tests",
       "//media/gpu:video_decode_accelerator_unittest",
       "//net/android:net_junit_tests",
+      "//services:services_junit_tests",

[blundell, 2017/05/10 14:51:57]

nit: this should be service_junit_tests to match service_unittests.

       "//testing/android/junit:junit_unit_tests",
       "//third_party/android_async_task:android_async_task_java",
       "//third_party/errorprone:chromium_errorprone",
       "//third_party/smhasher:murmurhash3",
       "//tools/android:android_tools",
       "//tools/android:memconsumer",
       "//tools/android:push_apps_to_background",
       "//tools/android/audio_focus_grabber:audio_focus_grabber_apk",
       "//tools/android/customtabs_benchmark:customtabs_benchmark_apk",
       "//tools/android/kerberos/SpnegoAuthenticator:spnego_authenticator_apk",
@@ skipping 799 matching lines @@
   assert(target_name != "")  # Mark as used.
   sources = invoker.actual_sources
   assert(
       sources == invoker.actual_sources,
       "Do not use a platform name in your output directory (found \"$root_build_dir\"). http://crbug.com/548283")
 }
 
 assert_valid_out_dir("_unused") {
   actual_sources = [ "$root_build_dir/foo" ]
 }