MIPSEL supports seccomp_bpf so use it with GN build as well

build/config/features.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.
 
 # This file contains UI-related build flags. It should theoretically be in the
 # src/ui directory and only things that depend on the ui module should get the
 # definitions.
 #
 # However, today we have many "bad" dependencies on some of these flags from,
 # e.g. base, so they need to be global.
@@ skipping 56 matching lines @@
 enable_basic_printing = !is_chromeos
 
 # Enable printing with print preview. It does not imply
 # enable_basic_printing. It's possible to build Chrome with preview only.
 enable_print_preview = !is_android
 
 # The seccomp-bpf sandbox is only supported on three architectures
 # currently.
 # Do not disable seccomp_bpf anywhere without talking to
 # security@chromium.org!
-use_seccomp_bpf = (is_linux || is_android) &&
-                  (cpu_arch == "x86" || cpu_arch == "x64" || cpu_arch == "arm")
+use_seccomp_bpf =
+    (is_linux || is_android) && (cpu_arch == "x86" || cpu_arch == "x64" ||
+                                 cpu_arch == "arm" || cpu_arch == "mipsel")
 
 # Enable notifications everywhere except iOS.
 enable_notifications = !is_ios
 
 # TODO(brettw) this should be moved to net and only dependents get this define.
 disable_ftp_support = is_ios
 
 enable_web_speech = !is_android && !is_ios
 
 use_dbus = is_linux
@@ skipping 68 matching lines @@
 
 # Option controlling the use of GConf (the classic GNOME configuration
 # system).
 # TODO(GYP) also require !embedded to enable.
 use_gconf = is_linux && !is_chromeos
 
 # Hangout services is an extension that adds extra features to Hangouts.
 # For official GYP builds, this flag is set, it will likely need to be
 # parameterized in the future for a similar use.
 enable_hangout_services_extension = false