Update from https://crrev.com/306655

net/quic/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/quic_utils.h"
 
 #include <ctype.h>
 
 #include <algorithm>
 #include <vector>
@@ skipping 241 matching lines @@
     RETURN_STRING_LITERAL(ALL_UNACKED_RETRANSMISSION);
     RETURN_STRING_LITERAL(ALL_INITIAL_RETRANSMISSION);
     RETURN_STRING_LITERAL(RTO_RETRANSMISSION);
     RETURN_STRING_LITERAL(TLP_RETRANSMISSION);
   }
   return "INVALID_TRANSMISSION_TYPE";
 }
 
 // static
 string QuicUtils::TagToString(QuicTag tag) {
-  char chars[4];
+  char chars[sizeof tag];
   bool ascii = true;
   const QuicTag orig_tag = tag;
 
-  for (size_t i = 0; i < sizeof(chars); i++) {
-    chars[i] = tag;
-    if ((chars[i] == 0 || chars[i] == '\xff') && i == 3) {
+  for (size_t i = 0; i < arraysize(chars); i++) {
+    chars[i] = static_cast<char>(tag);
+    if ((chars[i] == 0 || chars[i] == '\xff') && i == arraysize(chars) - 1) {
       chars[i] = ' ';
     }
     if (!isprint(static_cast<unsigned char>(chars[i]))) {
       ascii = false;
       break;
     }
     tag >>= 8;
   }
 
   if (ascii) {
@@ skipping 58 matching lines @@
 QuicPriority QuicUtils::LowestPriority() {
   return QuicWriteBlockedList::kLowestPriority;
 }
 
 // static
 QuicPriority QuicUtils::HighestPriority() {
   return QuicWriteBlockedList::kHighestPriority;
 }
 
 }  // namespace net