When HttpNetworkTransaction encounters QUIC errors, retry the request

net/http/http_network_transaction.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.
 
 #ifndef NET_HTTP_HTTP_NETWORK_TRANSACTION_H_
 #define NET_HTTP_HTTP_NETWORK_TRANSACTION_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 362 matching lines @@
   // read from the socket until the tunnel is done.
   bool establishing_tunnel_;
 
   // Enable pooling to a SpdySession with matching IP and certificate
   // even if the SpdySessionKey is different.
   bool enable_ip_based_pooling_;
 
   // Enable using alternative services for the request.
   bool enable_alternative_services_;
 
+  // When a request is retried because of errors with the alternative service,
+  // this will store the alternative service used.
+  AlternativeService retried_alternative_service_;

[ianswett, 2017/04/13 14:02:46]

This sort of mechanism could be useful for TFO and TLS 1.3(if there are
deployment issues with that), as well.

[Ryan Hamilton, 2017/04/13 17:26:56]

*nod* I don't think those systems use alternative services, but a retry-on-error
+ disable on success could definitely work!

+
   // The helper object to use to create WebSocketHandshakeStreamBase
   // objects. Only relevant when establishing a WebSocket connection.
   WebSocketHandshakeStreamBase::CreateHelper*
       websocket_handshake_stream_base_create_helper_;
 
   BeforeNetworkStartCallback before_network_start_callback_;
   BeforeHeadersSentCallback before_headers_sent_callback_;
 
   ConnectionAttempts connection_attempts_;
   IPEndPoint remote_endpoint_;
   // Network error details for this transaction.
   NetErrorDetails net_error_details_;
 
   // Communicate lifetime of transaction to the throttler, and
   // throttled state to the transaction.
   std::unique_ptr<NetworkThrottleManager::Throttle> throttle_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpNetworkTransaction);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_NETWORK_TRANSACTION_H_