Add base::UnguessableToken << operator

base/unguessable_token.cc

 // Copyright 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 "base/unguessable_token.h"
 
 #include "base/format_macros.h"
 #include "base/rand_util.h"
 #include "base/strings/stringprintf.h"
 
@@ skipping 16 matching lines @@
 }
 
 // static
 UnguessableToken UnguessableToken::Deserialize(uint64_t high, uint64_t low) {
   // Receiving a zeroed out UnguessableToken from another process means that it
   // was never initialized via Create(). Treat this case as a security issue.
   DCHECK(!(high == 0 && low == 0));
   return UnguessableToken(high, low);
 }
 
+std::ostream& operator<<(std::ostream& out, const UnguessableToken& token) {
+  return out << token.ToString();
+}
+
 }  // namespace base