Replace ENABLE_OPENTYPE_VERTICAL implementation with HarfBuzz

Source/config.gni

 # 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")
 
 if (is_android) {
   import("//build/config/android/config.gni")
 } else {
   # TODO(brettw) remove this once && early-out is checked in.
@@ skipping 66 matching lines @@
 
 if (use_openmax_dl_fft) {
   feature_defines_list += [
     "WTF_USE_WEBAUDIO_OPENMAX_DL_FFT=1",
     # Enabling the FFT is enough to enable WebAudio support to
     # allow most WebAudio features to work on Android.
     "ENABLE_WEB_AUDIO=1",
   ]
 }
 
-if (!is_mac) {
-  # Mac OS X has not implemented support for ENABLE(OPENTYPE_VERTICAL) yet.
-  feature_defines_list += [ "ENABLE_OPENTYPE_VERTICAL=1" ]
-}
-
 if (use_default_render_theme) {
   feature_defines_list += [ "WTF_USE_DEFAULT_RENDER_THEME=1" ]
 }
 if (enable_oilpan) {
   feature_defines_list += [ "ENABLE_OILPAN=1" ]
 }
 if (blink_asserts_always_on) {
   feature_defines_list += [ "ENABLE_ASSERT=1" ]
 }
 
 # feature_defines_string -------------------------------------------------------
 
 # Convert the list to a space-separated string for passing to scripts.
 # This would be the equivalent of passing '<(feature_defines)' in GYP.
 feature_defines_string = exec_script(
     "build/gn_list_to_space_separated_string.py",
     feature_defines_list,
     "trim string")