Move the test template to //testing/test.gni (part 2)

ui/app_list/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/ui.gni")
+import("//testing/rules.gni")
 
 component("app_list") {
   sources = [
     "app_list_constants.cc",
     "app_list_constants.h",
     "app_list_export.h",
     "app_list_folder_item.cc",
     "app_list_folder_item.h",
     "app_list_item.cc",
     "app_list_item.h",
@@ skipping 255 matching lines @@
       "cocoa/app_list_view_controller_unittest.mm",
       "cocoa/app_list_window_controller_unittest.mm",
       "cocoa/apps_grid_controller_unittest.mm",
       "cocoa/apps_search_box_controller_unittest.mm",
       "cocoa/apps_search_results_controller_unittest.mm",
       "cocoa/test/apps_grid_controller_test_helper.h",
       "cocoa/test/apps_grid_controller_test_helper.mm",
     ]
   }
 }