Certificate Transparency: Ensure timestamps over 32 bit are handled correctly.

net/cert/signed_tree_head.h

 // Copyright 2014 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.
 
 #ifndef NET_CERT_SIGNED_TREE_HEAD_H_
 #define NET_CERT_SIGNED_TREE_HEAD_H_
 
 #include <stdint.h>
 
 #include <iosfwd>
@@ skipping 31 matching lines @@
   base::Time timestamp;
   uint64_t tree_size;
   char sha256_root_hash[kSthRootHashLength];
   DigitallySigned signature;
 
   // Added in RFC6962-bis, Appendix A. Needed to identify which log
   // this STH belongs to.
   std::string log_id;
 };
 
-NET_EXPORT std::ostream& operator<<(std::ostream& stream,
-                                    const SignedTreeHead& sth);
+NET_EXPORT void PrintTo(const SignedTreeHead& sth, std::ostream* os);
 
 }  // namespace ct
 
 }  // namespace net
 
 #endif