Add an SignedCertificateTimetampStore, making SignedCertificateTimestamp be refcounted to aid.

net/cert/signed_certificate_timestamp.cc

 // Copyright 2013 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/cert/signed_certificate_timestamp.h"
 
 namespace net {
 
 namespace ct {
 
+bool SignedCertificateTimestamp::LessThan::operator()(
+    const scoped_refptr<SignedCertificateTimestamp>& lhs,
+    const scoped_refptr<SignedCertificateTimestamp>& rhs) const {
+  if (lhs.get() == rhs.get())
+    return false;
+
+  return lhs->signature.signature_data < rhs->signature.signature_data;
+}
+
 SignedCertificateTimestamp::SignedCertificateTimestamp() {}
 
 SignedCertificateTimestamp::~SignedCertificateTimestamp() {}
 
 LogEntry::LogEntry() {}
 
 LogEntry::~LogEntry() {}
 
 void LogEntry::Reset() {
   type = LogEntry::LOG_ENTRY_TYPE_X509;
   leaf_certificate.clear();
   tbs_certificate.clear();
 }
 
 DigitallySigned::DigitallySigned() {}
 
 DigitallySigned::~DigitallySigned() {}
 
 }  // namespace ct
 
 }  // namespace net