Moves QuicTag typedefs, and QuicTag utility methods to quic_tag.{h,cc}. No behavior change.

net/quic/core/quic_versions.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_versions.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "net/quic/core/quic_flags.h"
+#include "net/quic/core/quic_tag.h"
 #include "net/quic/core/quic_types.h"
 #include "net/quic/core/quic_utils.h"
 
 using base::StringPiece;
 using std::map;
 using std::numeric_limits;
 using std::ostream;
 using std::string;
 
 namespace net {
@@ skipping 56 matching lines @@
   }
 }
 
 QuicVersion QuicTagToQuicVersion(const QuicTag version_tag) {
   for (size_t i = 0; i < arraysize(kSupportedQuicVersions); ++i) {
     if (version_tag == QuicVersionToQuicTag(kSupportedQuicVersions[i])) {
       return kSupportedQuicVersions[i];
     }
   }
   // Reading from the client so this should not be considered an ERROR.
-  DVLOG(1) << "Unsupported QuicTag version: "
-           << QuicUtils::TagToString(version_tag);
+  DVLOG(1) << "Unsupported QuicTag version: " << QuicTagToString(version_tag);
   return QUIC_VERSION_UNSUPPORTED;
 }
 
 #define RETURN_STRING_LITERAL(x) \
   case x:                        \
     return #x
 
 string QuicVersionToString(const QuicVersion version) {
   switch (version) {
     RETURN_STRING_LITERAL(QUIC_VERSION_34);
     RETURN_STRING_LITERAL(QUIC_VERSION_35);
     RETURN_STRING_LITERAL(QUIC_VERSION_36);
     default:
       return "QUIC_VERSION_UNSUPPORTED";
   }
 }
 
 string QuicVersionVectorToString(const QuicVersionVector& versions) {
   string result = "";
   for (size_t i = 0; i < versions.size(); ++i) {
     if (i != 0) {
       result.append(",");
     }
     result.append(QuicVersionToString(versions[i]));
   }
   return result;
 }
 
 }  // namespace net