Update from https://crrev.com/305340

net/tools/quic/quic_server_session.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/tools/quic/quic_server_session.h"
 
 #include "base/logging.h"
 #include "net/quic/crypto/cached_network_parameters.h"
 #include "net/quic/quic_connection.h"
 #include "net/quic/quic_flags.h"
@@ skipping 20 matching lines @@
   crypto_stream_.reset(CreateQuicCryptoServerStream(crypto_config));
 }
 
 QuicCryptoServerStream* QuicServerSession::CreateQuicCryptoServerStream(
     const QuicCryptoServerConfig& crypto_config) {
   return new QuicCryptoServerStream(crypto_config, this);
 }
 
 void QuicServerSession::OnConfigNegotiated() {
   QuicSession::OnConfigNegotiated();
-  if (!FLAGS_enable_quic_fec ||
-      !config()->HasReceivedConnectionOptions() ||
-      !net::ContainsQuicTag(config()->ReceivedConnectionOptions(), kFHDR)) {
+
+  if (!config()->HasReceivedConnectionOptions()) {
     return;
   }
-  // kFHDR config maps to FEC protection always for headers stream.
-  // TODO(jri): Add crypto stream in addition to headers for kHDR.
-  headers_stream_->set_fec_policy(FEC_PROTECT_ALWAYS);
+
+  // If the client has provided a bandwidth estimate from the same serving
+  // region, then pass it to the sent packet manager in preparation for possible
+  // bandwidth resumption.
+  const CachedNetworkParameters* cached_network_params =
+      crypto_stream_->previous_cached_network_params();
+  if (FLAGS_quic_enable_bandwidth_resumption_experiment &&
+      cached_network_params != nullptr &&
+      ContainsQuicTag(config()->ReceivedConnectionOptions(), kBWRE) &&
+      cached_network_params->serving_region() == serving_region_) {
+    connection()->ResumeConnectionState(*cached_network_params);
+  }
+
+  if (FLAGS_enable_quic_fec &&
+      ContainsQuicTag(config()->ReceivedConnectionOptions(), kFHDR)) {
+    // kFHDR config maps to FEC protection always for headers stream.
+    // TODO(jri): Add crypto stream in addition to headers for kHDR.
+    headers_stream_->set_fec_policy(FEC_PROTECT_ALWAYS);
+  }
 }
 
 void QuicServerSession::OnConnectionClosed(QuicErrorCode error,
                                            bool from_peer) {
   QuicSession::OnConnectionClosed(error, from_peer);
   // In the unlikely event we get a connection close while doing an asynchronous
   // crypto event, make sure we cancel the callback.
   if (crypto_stream_.get() != nullptr) {
     crypto_stream_->CancelOutstandingCallbacks();
   }
@@ skipping 115 matching lines @@
   DLOG(ERROR) << "Server push not yet supported";
   return nullptr;
 }
 
 QuicCryptoServerStream* QuicServerSession::GetCryptoStream() {
   return crypto_stream_.get();
 }
 
 }  // namespace tools
 }  // namespace net