Land Recent QUIC changes.

net/quic/quic_utils.h

 // 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.
 //
 // Some helpers for quic
 
 #ifndef NET_QUIC_QUIC_UTILS_H_
 #define NET_QUIC_QUIC_UTILS_H_
 
 #include "net/base/int128.h"
 #include "net/base/net_export.h"
 #include "net/quic/quic_protocol.h"
 
 namespace net {
 
 class NET_EXPORT_PRIVATE QuicUtils {
  public:
+  enum Priority {
+    LOCAL_PRIORITY,
+    PEER_PRIORITY,
+  };
+
   // returns the 64 bit FNV1a hash of the data.  See
   // http://www.isthe.com/chongo/tech/comp/fnv/index.html#FNV-param
   static uint64 FNV1a_64_Hash(const char* data, int len);
 
   // returns the 128 bit FNV1a hash of the data.  See
   // http://www.isthe.com/chongo/tech/comp/fnv/index.html#FNV-param
   static uint128 FNV1a_128_Hash(const char* data, int len);
 
+  // FindMutualTag sets |out_result| to the first tag in the priority list that
+  // is also in the other list and returns true. If there is no intersection it
+  // returns false.
+  //
+  // Which list has priority is determined by |priority|.
+  //
+  // If |out_index| is non-NULL and a match is found then the index of that
+  // match in |their_tags| is written to |out_index|.
+  static bool FindMutualTag(const QuicTagVector& our_tags,
+                            const QuicTag* their_tags,
+                            size_t num_their_tags,
+                            Priority priority,
+                            QuicTag* out_result,
+                            size_t* out_index);
+
   // SerializeUint128 writes |v| in little-endian form to |out|.
   static void SerializeUint128(uint128 v, uint8* out);
 
   // ParseUint128 parses a little-endian uint128 from |in| and returns it.
   static uint128 ParseUint128(const uint8* in);
 
   // Returns the name of the QuicRstStreamErrorCode as a char*
   static const char* StreamErrorToString(QuicRstStreamErrorCode error);
 
   // Returns the name of the QuicErrorCode as a char*
   static const char* ErrorToString(QuicErrorCode error);
+
+  // TagToString is a utility function for pretty-printing handshake messages
+  // that converts a tag to a string. It will try to maintain the human friendly
+  // name if possible (i.e. kABCD -> "ABCD"), or will just treat it as a number
+  // if not.
+  static std::string TagToString(QuicTag tag);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_UTILS_H_