mash: Port mojo:ash_sysui's ContextMenuMus to mojo:ash.

ash/mus/BUILD.gn

 # Copyright 2015 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("//mojo/public/tools/bindings/mojom.gni")
 import("//services/shell/public/cpp/service.gni")
 import("//services/shell/public/service_manifest.gni")
 import("//tools/grit/repack.gni")
 
@@ skipping 16 matching lines @@
     "bridge/wm_root_window_controller_mus.cc",
     "bridge/wm_root_window_controller_mus.h",
     "bridge/wm_shelf_mus.cc",
     "bridge/wm_shelf_mus.h",
     "bridge/wm_shell_mus.cc",
     "bridge/wm_shell_mus.h",
     "bridge/wm_window_mus.cc",
     "bridge/wm_window_mus.h",
     "container_ids.cc",
     "container_ids.h",
+    "context_menu_mus.cc",
+    "context_menu_mus.h",
     "disconnected_app_handler.cc",
     "disconnected_app_handler.h",
     "drag_window_resizer.cc",
     "drag_window_resizer.h",
     "layout_manager.cc",
     "layout_manager.h",
     "move_event_handler.cc",
     "move_event_handler.h",
+    "native_widget_factory_mus.cc",
+    "native_widget_factory_mus.h",
     "new_window_delegate_mus.cc",
     "new_window_delegate_mus.h",
     "non_client_frame_controller.cc",
     "non_client_frame_controller.h",
     "property_util.cc",
     "property_util.h",
     "root_window_controller.cc",
     "root_window_controller.h",
     "screenlock_layout.cc",
     "screenlock_layout.h",
@@ skipping 158 matching lines @@
     "//ui/views/mus",
   ]
 
   data_deps = [
     ":mus",
     "//mash/quick_launch",
   ]
 
   defines = [ "NOTIMPLEMENTED_POLICY=5" ]
 }