Use Ash's ShelfWindowWatcher for app panel windows.

ash/BUILD.gn

 # Copyright 2014 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/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
 
 assert(use_aura)
@@ skipping 1339 matching lines @@
     "wm/workspace_controller_test_helper.h",
     "wm/workspace_controller_unittest.cc",
   ]
   configs += [
     "//build/config:precompiled_headers",
     "//build/config/compiler:no_size_t_to_int_warning",
   ]
 
   deps = [
     ":ash",
+    ":ash_shell_lib",

[James Cook, 2016/11/10 22:32:46]

Why is this needed? ash_shell should just be the little ash runtime environment.
I wouldn't expect it to be needed for tests.

Is there a stub that needs to be moved into shared test code?

[msw, 2016/11/10 23:30:52]

Reverted; this let ShelfWindowWatcherTest use PanelWindow.

     "//ash/autoclick/common:autoclick",
     "//ash/common:unittests",
     "//ash/common/strings",
     "//ash/common/test:test_support",
     "//ash/public/cpp",
     "//ash/resources",
     "//ash/test:ash_with_aura_test_support",
     "//ash/test:test_support_without_content",
     "//ash/touch_hud",
     "//base",
@@ skipping 123 matching lines @@
   if (is_win) {
     configs -= [ "//build/config/win:console" ]
     configs += [ "//build/config/win:windowed" ]
     deps += [ "//sandbox" ]
   }
 
   if (is_chromeos) {
     deps += [ "//device/bluetooth" ]
   }
 }