Add static domain security state generator tool.

net/tools/domain_security_preload_generator/domain_security_entry.cc

Index: net/tools/domain_security_preload_generator/domain_security_entry.cc
diff --git a/net/tools/domain_security_preload_generator/domain_security_entry.cc b/net/tools/domain_security_preload_generator/domain_security_entry.cc
new file mode 100644
index 0000000000000000000000000000000000000000..cbc8a86c4c6e9a066c288ca68fdcee32c27dd1c0
--- /dev/null
+++ b/net/tools/domain_security_preload_generator/domain_security_entry.cc
@@ -0,0 +1,15 @@
+// Copyright (c) 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.
+#include "net/tools/domain_security_preload_generator/domain_security_entry.h"
+
+namespace net {
+
+namespace transport_security_state {
+
+DomainSecurityEntry::DomainSecurityEntry() {}
+DomainSecurityEntry::~DomainSecurityEntry() {}
+
+}  // namespace transport_security_state
+
+}  // namespace