WIP: simplified display management in ash

ash/mus/standalone/BUILD.gn

+# Copyright 2017 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("//services/service_manager/public/cpp/service.gni")
+import("//services/service_manager/public/service_manifest.gni")
+
+assert(is_chromeos)
+
+service("standalone_ash") {
+  output_name = "standalone_ash"
+  testonly = true
+
+  sources = [
+    "standalone_mash_main.cc",
+  ]
+
+  deps = [
+    "//ash:ash_shell_lib",
+    "//ash/mus:lib",
+    "//ash/mus:resources",
+    "//ash/mus:resources_200",
+    "//services/service_manager/public/cpp",
+    "//services/ui/public/cpp/input_devices",
+    "//services/ui/public/interfaces",
+    "//ui/app_list/presenter",
+    "//ui/views/examples:views_examples_lib",
+  ]
+
+  # TODO(beng): This target relies on //mash/session, but there is a cycle so we
+  #             can't state that dependency here.
+  data_deps = [
+    "//ash/mus:resources",
+    "//ash/mus:resources_200",
+    "//services/ui",
+  ]
+}
+
+service_manifest("manifest") {
+  name = "standalone_ash"
+  source = "manifest.json"
+}