Add a build flag to configure bundling of HSTS preload list

net/tools/transport_security_state_generator/transport_security_state_generator.cc

Index: net/tools/transport_security_state_generator/transport_security_state_generator.cc
diff --git a/net/tools/transport_security_state_generator/transport_security_state_generator.cc b/net/tools/transport_security_state_generator/transport_security_state_generator.cc
index 40e8f1d3c42a4eafe154710680bab21075525097..cadad15890c72558ce639e5e28b00a5980c73713 100644
--- a/net/tools/transport_security_state_generator/transport_security_state_generator.cc
+++ b/net/tools/transport_security_state_generator/transport_security_state_generator.cc
@@ -26,10 +26,17 @@ using net::transport_security_state::PreloadedStateGenerator;
 
 namespace {
 
+// If true, the entire preload list will be included. Otherwise, only include
+// the first entry to allow the generator to generate a valid file.

[Ryan Sleevi, 2017/06/29 20:47:41]

This seems a bit suboptimal - that is, wouldn't it be better not to generate the
file / call the generator? Could you explain more why this approach?

[xunjieli, 2017/06/30 19:12:18]

Done. The Huffman tree decoding code expects at least one entry. I have reverted
this and modified transport_security_state.cc.

+static const char kIncludeTransportSecurityStatePreloadListSwitch[] =
+    "include-transport-security-state-preload-list";
+
 // Print the command line help.
 void PrintHelp() {
   std::cout << "transport_security_state_generator <json-file> <pins-file>"
-            << " <template-file> <output-file> [--v=1]" << std::endl;
+            << " <template-file> <output-file> [--v=1] "
+               "[--exclude-hsts-preload-list=false]"
+            << std::endl;
 }
 
 // Checks if there are pins with the same name or the same hash.
@@ -278,6 +285,16 @@ int main(int argc, char* argv[]) {
     return 1;
   }
 
+  std::string include_transport_security_state_preload_list_string =
+      command_line.GetSwitchValueASCII(
+          kIncludeTransportSecurityStatePreloadListSwitch);
+  if (include_transport_security_state_preload_list_string == "true") {
+    // Keep only one entry enough to make trie generation pass.
+    entries.erase(++entries.begin(), entries.end());
+    std::set<std::string> required_pinsets = {entries[0]->pinset};
+    pinsets.FilterPinsets(required_pinsets);
+  }
+
   std::string output;
   PreloadedStateGenerator generator;
   output = generator.Generate(preload_template, entries, pinsets);