Use struct AlternativeService in OnAltSvc() and OnSpdyAltSvc() methods.

net/spdy/spdy_alt_svc_wire_format.h

 // Copyright (c) 2015 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.
 
 // This file contains data structures and utility functions used for serializing
 // and parsing alternative service header values, common to HTTP/1.1 header
 // fields and HTTP/2 and QUIC ALTSVC frames.  See specification at
 // https://tools.ietf.org/id/draft-ietf-httpbis-alt-svc-06.html
 
 #ifndef NET_SPDY_SPDY_ALT_SVC_WIRE_FORMAT_H_
 #define NET_SPDY_SPDY_ALT_SVC_WIRE_FORMAT_H_
 
 #include "base/basictypes.h"
 #include "base/strings/string_piece.h"
 #include "net/base/net_export.h"
 
 using base::StringPiece;
 
 namespace net {
 
 namespace test {
 class SpdyAltSvcWireFormatPeer;
 }  // namespace test
 
 class NET_EXPORT_PRIVATE SpdyAltSvcWireFormat {
  public:
+  struct AlternativeService {
+    std::string protocol_id;
+    std::string host;
+    uint16 port = 0;
+    uint32 max_age = 0;
+    double p = 1.0;
+
+    bool operator==(const AlternativeService& other) const {
+      return protocol_id == other.protocol_id && host == other.host &&
+             port == other.port && max_age == other.max_age && p == other.p;
+    }
+  };
+
   friend class test::SpdyAltSvcWireFormatPeer;
   static bool ParseHeaderFieldValue(StringPiece value,
-                                    std::string* protocol_id,
-                                    std::string* host,
-                                    uint16* port,
-                                    uint32* max_age,
-                                    double* p);
-  static std::string SerializeHeaderFieldValue(const std::string& protocol_id,
-                                               const std::string& host,
-                                               uint16 port,
-                                               uint32 max_age,
-                                               double p);
+                                    AlternativeService* altsvc);
+  static std::string SerializeHeaderFieldValue(
+      const AlternativeService& altsvc);
 
  private:
   static void SkipWhiteSpace(StringPiece::const_iterator* c,
                              StringPiece::const_iterator end);
   static bool PercentDecode(StringPiece::const_iterator c,
                             StringPiece::const_iterator end,
                             std::string* output);
   static bool ParseAltAuthority(StringPiece::const_iterator c,
                                 StringPiece::const_iterator end,
                                 std::string* host,
                                 uint16* port);
   static bool ParsePositiveInteger16(StringPiece::const_iterator c,
                                      StringPiece::const_iterator end,
                                      uint16* value);
   static bool ParsePositiveInteger32(StringPiece::const_iterator c,
                                      StringPiece::const_iterator end,
                                      uint32* value);
   static bool ParseProbability(StringPiece::const_iterator c,
                                StringPiece::const_iterator end,
                                double* p);
 };
 
 }  // namespace net
 
 #endif  // NET_SPDY_SPDY_ALT_SVC_WIRE_FORMAT_H_