Add a build flag to configure bundling of HSTS preload list

net/features.gni

 # 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")
 
 declare_args() {
   # If true, prune things down as needed for proto-quic build.
   is_proto_quic = false
 
@@ skipping 12 matching lines @@
   use_kerberos = !is_ios && !is_chromecast
 
   # Do not disable brotli filter by default.
   disable_brotli_filter = false
 
   # Multicast DNS.
   enable_mdns = is_win || is_linux
 
   # Reporting not used on iOS.
   enable_reporting = !is_ios
+
+  # Includes the transport security state preload list. This list includes
+  # mechanisms (e.g. HSTS, HPKP) to enforce trusted connections to a significant
+  # set of hardcoded domains. While this list has a several hundred KB of binary
+  # size footprint, this flag should not be disabled unless the embedder is
+  # willing to take the responsibility to make sure that all important
+  # connections use HTTPS.
+  include_transport_security_state_preload_list = true
 }