Build HarfBuzz as loadable module when chromeos=1 under Linux

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 20 matching lines @@
     "//base/third_party/dynamic_annotations",
     "//cc",
     "//components/device_event_log",
     "//components/onc",
     "//components/signin/core/account_id",
     "//components/user_manager",
     "//components/wallpaper",
     "//media",
     "//net",
     "//skia",
+    "//third_party/harfbuzz-ng",
     "//third_party/icu",
     "//ui/accessibility",
     "//ui/app_list",
     "//ui/aura",
     "//ui/base",
     "//ui/base:ui_data_pack",
     "//ui/base/ime",
     "//ui/compositor",
     "//ui/display/types",
     "//ui/events",
@@ skipping 424 matching lines @@
     configs += [ "//build/config/win:windowed" ]
     deps += [ "//sandbox" ]
   }
 
   if (is_chromeos) {
     deps += [ "//device/bluetooth" ]
   }
 }
 # When adding support for isolates, please have a look at run-time dependencies
 # in the ash_unittests_run target in ash.gyp.