Add a build flag to configure bundling of HSTS preload list

net/http/transport_security_state_source.h

 // Copyright (c) 2017 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.
 
 #ifndef NET_HTTP_TRANSPORT_SECURITY_STATE_SOURCE_H_
 #define NET_HTTP_TRANSPORT_SECURITY_STATE_SOURCE_H_
 
+#include <stddef.h>
+#include <stdint.h>
+
+#include "net/base/net_export.h"
+
 namespace net {
 
+// kNoReportURI is a placeholder for when a pinset does not have a report URI.
+NET_EXPORT_PRIVATE extern const char kNoReportURI[];
+
 struct TransportSecurityStateSource {
   struct Pinset {
     const char* const* const accepted_pins;
     const char* const* const rejected_pins;
     const char* const report_uri;
   };
 
   const uint8_t* huffman_tree;
   size_t huffman_tree_size;
   const uint8_t* preloaded_data;
   size_t preloaded_bits;
   size_t root_position;
   const char* const* expect_ct_report_uris;
   const char* const* expect_staple_report_uris;
   const Pinset* pinsets;
   size_t pinsets_count;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_TRANSPORT_SECURITY_STATE_SOURCE_H_