Revert of Validate origins when generating subdomain tokens

build/config/linux/gconf/BUILD.gn

 # Copyright 2016 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/linux/pkg_config.gni")
 
 # CrOS doesn't install GTK, gconf or any gnome packages.
 assert(!is_chromeos && use_gconf)
 
+# These packages should _only_ be expected when building for a target.
+# If these extra checks are not run, gconf is required when building host
+# tools for a CrOS build.
+assert(current_toolchain == default_toolchain)
+
 pkg_config("gconf") {
   packages = [ "gconf-2.0" ]
   defines = [ "USE_GCONF" ]
 }