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

ui/display/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("display") {
   sources = [
     "chromeos/configure_displays_task.cc",
     "chromeos/configure_displays_task.h",
     "chromeos/display_configurator.cc",
     "chromeos/display_configurator.h",
     "chromeos/display_util.cc",
     "chromeos/display_util.h",
     "chromeos/ozone/display_configurator_ozone.cc",
@@ skipping 133 matching lines @@
     ]
   }
 
   if (use_ozone && is_chromeos) {
     sources -= [
       "chromeos/x11/display_util_x11_unittest.cc",
       "chromeos/x11/native_display_event_dispatcher_x11_unittest.cc",
     ]
   }
 }