Add a build flag to configure bundling of HSTS preload list

net/http/transport_security_state_static.template

 // Copyright (c) 2012 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 is generated by net/tools/transport_security_state_generator/.
 
 #ifndef NET_HTTP_TRANSPORT_SECURITY_STATE_STATIC_H_
 #define NET_HTTP_TRANSPORT_SECURITY_STATE_STATIC_H_
 
 #include <stdint.h>
 
 #include "net/http/transport_security_state_source.h"
 
+// kNoReportURI is a placeholder for when a pinset does not have a report URI.
+static const char kNoReportURI[] = "";
+
+#if BUILDFLAG(INCLUDE_TRANSPORT_SECURITY_STATE_PRELOAD_LIST)
+
 // These are SubjectPublicKeyInfo hashes for public key pinning. The
 // hashes are SHA256 digests.
 [[SPKI_HASHES]]
 
 static const char* const kExpectCTReportURIs[] = [[EXPECT_CT_REPORT_URIS]];
 
 static const char* const kExpectStapleReportURIs[] = [[EXPECT_STAPLE_REPORT_URIS]];
 
 // kNoRejectedPublicKeys is a placeholder for when no public keys are rejected.
 static const char* const kNoRejectedPublicKeys[] = {
     nullptr,
 };
 
-// kNoReportURI is a placeholder for when a pinset does not have a report URI.
-static const char kNoReportURI[] = "";
-
 [[ACCEPTABLE_CERTS]]
 
 static const net::TransportSecurityStateSource::Pinset kPinsets[] = [[PINSETS]];
 
 // kHSTSHuffmanTree describes a Huffman tree. The nodes of the tree are pairs
 // of uint8s. The last node in the array is the root of the tree. Each pair is
 // two uint8_t values, the first is "left" and the second is "right". If a
 // uint8_t value has the MSB set then it represents a literal leaf value.
 // Otherwise it's a pointer to the n'th element of the array.
 static const uint8_t kHSTSHuffmanTree[] = [[HUFFMAN_TREE]];
 
 static const uint8_t kPreloadedHSTSData[] = [[HSTS_TRIE]];
 
 static const unsigned kPreloadedHSTSBits = [[HSTS_TRIE_BITS]];
 static const unsigned kHSTSRootPosition = [[HSTS_TRIE_ROOT]];
 
 static const net::TransportSecurityStateSource kHSTSSource = {
   kHSTSHuffmanTree,
   sizeof(kHSTSHuffmanTree),
   kPreloadedHSTSData,
   kPreloadedHSTSBits,
   kHSTSRootPosition,
   kExpectCTReportURIs,
   kExpectStapleReportURIs,
   kPinsets,
   arraysize(kPinsets)
 };
 
+#else
+static const net::TransportSecurityStateSource kHSTSSource = {

[Ryan Sleevi, 2017/07/07 16:45:13]

I'm not sure it makes sense to force the BUILDFLAG into the template - it seems
cleaner to remove this dependency entirely if the build flag is not set.

Could you explain more the reasoning?

[xunjieli, 2017/07/10 22:20:40]

Done. Not compiling this when the build flag is turned off is definitely much
cleaner. Thanks for the suggestion.

+  nullptr,
+  0,
+  nullptr,
+  0,
+  0,
+  nullptr,
+  nullptr,
+  nullptr,
+  0
+};
+#endif  // BUILDFLAG(INCLUDE_TRANSPORT_SECURITY_STATE_PRELOAD_LIST)
+
 #endif  // NET_HTTP_TRANSPORT_SECURITY_STATE_STATIC_H_