Makes AshTestImpl::Create create the right impl based on config

chrome/test/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/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
@@ skipping 222 matching lines @@
   }
 
   if (use_ash) {
     sources += [
       "base/default_ash_event_generator_delegate.cc",
       "base/default_ash_event_generator_delegate.h",
     ]
 
     public_deps += [
       "//ash",
-      "//ash/test:ash_with_aura_test_support",
       "//ash/test:test_support_with_content",
       "//ui/aura",
       "//ui/aura:test_support",
     ]
   }
   if (toolkit_views) {
     public_deps += [ "//ui/views:test_support" ]
   }
 
   if (enable_extensions) {
@@ skipping 1866 matching lines @@
         "../browser/ui/ash/multi_user/multi_user_window_manager_test.cc",
         "../browser/ui/ash/multi_user/multi_user_window_manager_test.h",
         "../browser/ui/ash/networking_config_delegate_chromeos_browsertest.cc",
         "../browser/ui/ash/shelf_browsertest.cc",
         "../browser/ui/ash/system_tray_client_browsertest.cc",
         "../browser/ui/ash/system_tray_delegate_chromeos_browsertest_chromeos.cc",
         "../browser/ui/ash/volume_controller_browsertest.cc",
         "../browser/ui/views/frame/browser_non_client_frame_view_ash_browsertest.cc",
       ]
       deps += [
-        "//ash/test:ash_with_aura_test_support",
         "//ash/test:test_support_with_content",
         "//ui/keyboard:test_support",
       ]
 
       if (enable_app_list) {
         deps += [ ":test_support_applist_ash" ]
       }
 
       if (enable_media_router) {
         sources += [ "../browser/ui/ash/system_tray_tray_cast_browsertest_media_router_chromeos.cc" ]
@@ skipping 2063 matching lines @@
       "../browser/ui/ash/multi_user/multi_user_util_chromeos_unittest.cc",
       "../browser/ui/ash/multi_user/multi_user_window_manager_chromeos_unittest.cc",
       "../browser/ui/ash/multi_user/user_switch_util_unittest.cc",
       "../browser/ui/ash/session_controller_client_unittest.cc",
       "../browser/ui/ash/window_positioner_unittest.cc",
       "../browser/ui/window_sizer/window_sizer_ash_unittest.cc",
     ]
     deps += [
       "//ash/resources",
       "//ash/strings",
-      "//ash/test:ash_with_aura_test_support",
       "//ash/test:test_support_with_content",
     ]
 
     # Chrome OS uses window_sizer_ash_unittest.cc
     sources -= [ "../browser/ui/window_sizer/window_sizer_unittest.cc" ]
   }
   if (use_aura) {
     deps += [
       "//ui/aura:test_support",
       "//ui/views:test_support",
@@ skipping 1005 matching lines @@
 }
 
 if (is_win) {
   loadable_module("conflicts_dll") {
     testonly = true
     sources = [
       "conflicts/conflicts_dll.cc",
     ]
   }
 }