chromeos: Introduce ash::SystemTrayTestApi

ash/test/BUILD.gn

 # Copyright 2016 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")
 
 static_library("test_support_without_content") {
   testonly = true
   sources = [
     "ash_test_environment_default.cc",
@@ skipping 31 matching lines @@
 
 # Internal target consumed by |test_support_with_content| and
 # |test_support_without_content|. This target contains all the test support
 # files, with the exception of an implementation of AshTestEnvironment.
 # Consumers of ash should use one of |test_support_with_content| or
 # |test_support_without_content|.
 static_library("test_support_common") {
   testonly = true
   visibility = [ ":*" ]
   sources = [
-    # TODO(jamescook): Move these files into ash/test.
     "../laser/laser_pointer_controller_test_api.cc",
     "../laser/laser_pointer_controller_test_api.h",
     "../laser/laser_pointer_points_test_api.cc",
     "../laser/laser_pointer_points_test_api.h",
     "../rotator/test/screen_rotation_animator_test_api.cc",
     "../rotator/test/screen_rotation_animator_test_api.h",
     "../shell/toplevel_window.cc",
     "../shell/toplevel_window.h",
+    "../system/tray/system_tray_test_api.h",
     "ash_test_base.cc",
     "ash_test_base.h",
     "ash_test_environment.h",
     "ash_test_helper.cc",
     "ash_test_helper.h",
     "ash_test_views_delegate.cc",
     "ash_test_views_delegate.h",
     "child_modal_window.cc",
     "child_modal_window.h",
     "cursor_manager_test_api.cc",
@@ skipping 128 matching lines @@
   deps = [
     ":test_support_with_content",
     "//base",
     "//skia",
     "//testing/gtest",
     "//ui/aura",
     "//ui/base",
     "//ui/gl:test_support",
   ]
 }