Remove QuicUtils::ListTags and use ToDebugString() instead.

net/quic/core/quic_utils.cc

 // Copyright (c) 2012 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/quic/core/quic_utils.h"
 
 #include <ctype.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 363 matching lines @@
     uint32_t option = 0;
     for (char token_char : base::Reversed(token)) {
       option <<= 8;
       option |= static_cast<unsigned char>(token_char);
     }
     options.push_back(option);
   }
   return options;
 }
 
-string QuicUtils::ListTags(QuicTagValueMap tag_map) {
-  string result;
-  for (auto entry : tag_map) {
-    result.append(TagToString(entry.first) + " ");
-  }
-  return result;
-}
-
 string QuicUtils::PeerAddressChangeTypeToString(PeerAddressChangeType type) {
   switch (type) {
     RETURN_STRING_LITERAL(NO_CHANGE);
     RETURN_STRING_LITERAL(PORT_CHANGE);
     RETURN_STRING_LITERAL(IPV4_SUBNET_CHANGE);
     RETURN_STRING_LITERAL(IPV4_TO_IPV6_CHANGE);
     RETURN_STRING_LITERAL(IPV6_TO_IPV4_CHANGE);
     RETURN_STRING_LITERAL(IPV6_TO_IPV6_CHANGE);
     RETURN_STRING_LITERAL(UNSPECIFIED_CHANGE);
   }
@@ skipping 171 matching lines @@
 
     bytes_remaining -= line_bytes;
     offset += line_bytes;
     p += line_bytes;
     s += '\n';
   }
   return s;
 }
 
 }  // namespace net