mustash: Fix crash when clicking on network in system tray

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 123 matching lines @@
       "system_tray_delegate_mus.cc",
       "system_tray_delegate_mus.h",
       "vpn_delegate_mus.cc",
       "vpn_delegate_mus.h",
     ]
 
     deps += [
       "//chromeos",
       "//chromeos:power_manager_proto",
       "//device/bluetooth",
+      "//ui/chromeos",
     ]
   }
 }
 
 service("mus") {
   output_name = "ash"
 
   sources = [
     "main.cc",
   ]
@@ skipping 138 matching lines @@
     "//mash/quick_launch",
   ]
 
   defines = [ "NOTIMPLEMENTED_POLICY=5" ]
 
   if (is_chromeos) {
     sources +=
         [ "../common/system/chromeos/brightness/tray_brightness_unittest.cc" ]
   }
 }