Support a user-provided string for the TLS ALPN extension.

webrtc/p2p/base/portallocator.h

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 173 matching lines @@
     return type == o.type && ports == o.ports && credentials == o.credentials &&
            priority == o.priority;
   }
   bool operator!=(const RelayServerConfig& o) const { return !(*this == o); }
 
   RelayType type;
   PortList ports;
   RelayCredentials credentials;
   int priority = 0;
   TlsCertPolicy tls_cert_policy = TlsCertPolicy::TLS_CERT_POLICY_SECURE;
+  std::vector<std::string> tls_alpn_protocols;
 };
 
 class PortAllocatorSession : public sigslot::has_slots<> {
  public:
   // Content name passed in mostly for logging and debugging.
   PortAllocatorSession(const std::string& content_name,
                        int component,
                        const std::string& ice_ufrag,
                        const std::string& ice_pwd,
                        uint32_t flags);
@@ skipping 298 matching lines @@
   std::deque<std::unique_ptr<PortAllocatorSession>> pooled_sessions_;
   bool candidate_pool_frozen_ = false;
   bool prune_turn_ports_ = false;
 
   webrtc::MetricsObserverInterface* metrics_observer_ = nullptr;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_PORTALLOCATOR_H_