Rename is_chromeos in chrome/src.

remoting/remoting_locales.gni

Index: remoting/remoting_locales.gni
diff --git a/remoting/remoting_locales.gni b/remoting/remoting_locales.gni
index b37d177b8e052e075420da1af310d8b8fd830ed1..7bd050c55de3aa0d57601d0e1687ce3867c8d2de 100644
--- a/remoting/remoting_locales.gni
+++ b/remoting/remoting_locales.gni
@@ -2,6 +2,8 @@
 # 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")
+
 webapp_locale_dir = "$root_gen_dir/remoting/webapp/_locales"
 
 # See also remoting_locales_with_underscores below.
@@ -92,13 +94,13 @@ remoting_locales_with_underscores += [
   "zh_TW",
 ]
 
-if (is_chromeos) {
+if (use_cros_fe) {
   remoting_locales += [ "en-US" ]
   remoting_locales_with_underscores += [ "en_US" ]
 }
 
 messages_locales = remoting_locales_with_underscores
-if (!is_chromeos) {
+if (!use_cros_fe) {
   # The messages output includes a separate one for en-US that the pak ones
   # don't have. We don't need to do this on ChromeOS since en_US is in the
   # locales list be default there.