Pull buildtools to get GN 295140

ui/ozone/platform/dri/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/linux/pkg_config.gni")
 import("//ui/ozone/ozone.gni")
 
 pkg_config("libdrm") {
   packages = [ "libdrm" ]
 }
@@ skipping 70 matching lines @@
 
     deps = [
       ":dri_common",
       "//base",
       "//skia",
       "//ui/events/ozone:events_ozone_evdev",
     ]
   }
 
   source_set("dri_unittests") {
+    testonly = true
     sources = [
       "dri_surface_factory_unittest.cc",
       "dri_surface_unittest.cc",
       "hardware_display_controller_unittest.cc",
       "screen_manager_unittest.cc",
       "test/mock_dri_wrapper.cc",
       "test/mock_dri_wrapper.h",
     ]
 
     deps = [
@@ skipping 41 matching lines @@
       "//base",
       "//skia",
       "//ui/events/ozone:events_ozone_evdev",
     ]
 
     direct_dependent_configs = [
       ":libgbm",
     ]
   }
 }