Add an SignedCertificateTimetampStore, making SignedCertificateTimestamp be refcounted to aid.

net/cert/signed_certificate_timestamp.cc

Index: net/cert/signed_certificate_timestamp.cc
diff --git a/net/cert/signed_certificate_timestamp.cc b/net/cert/signed_certificate_timestamp.cc
index 0be511d41dbb64cde0fe151d0ee41f40e664eb3d..8925a994c123ba146f30bfd2bb8c8cd5fa4d975a 100644
--- a/net/cert/signed_certificate_timestamp.cc
+++ b/net/cert/signed_certificate_timestamp.cc
@@ -8,6 +8,22 @@ 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;
+  if (lhs->signature.signature_data != rhs->signature.signature_data)
+    return lhs->signature.signature_data < rhs->signature.signature_data;
+  if (lhs->log_id != rhs->log_id)
+    return lhs->log_id < rhs->log_id;
+  if (lhs->timestamp != rhs->timestamp)
+    return lhs->timestamp < rhs->timestamp;
+  if (lhs->extensions != rhs->extensions)
+    return lhs->extensions < rhs->extensions;
+  return lhs->version < rhs->version;
+}
+
 SignedCertificateTimestamp::SignedCertificateTimestamp() {}
 
 SignedCertificateTimestamp::~SignedCertificateTimestamp() {}