Rename is_chromeos in chrome/src.

chromeos/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/allocator.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//third_party/protobuf/proto_library.gni")
 
-assert(is_chromeos, "Non-ChromeOS builds must not depend on //chromeos")
+assert(use_cros_fe, "Non-ChromeOS builds must not depend on //chromeos")
 
 gypi_values = exec_script("//build/gypi_to_gn.py",
                           [ rebase_path("chromeos.gyp") ],
                           "scope",
                           [ "chromeos.gyp" ])
 
 component("chromeos") {
   configs += [ "//net/third_party/nss/ssl:ssl_config" ]
   public_deps = [
     "//dbus",
@@ skipping 151 matching lines @@
   proto_out_dir = "chromeos/dbus/cryptohome"
 }
 
 proto_library("cryptohome_signkey_proto") {
   sources = [
     "//third_party/cros_system_api/dbus/cryptohome/signed_secret.proto",
   ]
 
   proto_out_dir = "chromeos/cryptohome"
 }