Update from https://crrev.com/311076

net/quic/quic_stream_factory.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/quic/quic_stream_factory.h"
 
 #include <set>
 
 #include "base/cpu.h"
 #include "base/message_loop/message_loop.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/rand_util.h"
 #include "base/stl_util.h"
 #include "base/strings/string_util.h"
 #include "base/values.h"
 #include "net/base/net_errors.h"
 #include "net/cert/cert_verifier.h"
 #include "net/dns/host_resolver.h"
 #include "net/dns/single_request_host_resolver.h"
 #include "net/http/http_server_properties.h"
 #include "net/quic/congestion_control/tcp_receiver.h"
 #include "net/quic/crypto/channel_id_chromium.h"
 #include "net/quic/crypto/proof_verifier_chromium.h"
 #include "net/quic/crypto/quic_random.h"
 #include "net/quic/crypto/quic_server_info.h"
 #include "net/quic/port_suggester.h"
 #include "net/quic/quic_client_session.h"
 #include "net/quic/quic_clock.h"
 #include "net/quic/quic_connection.h"
 #include "net/quic/quic_connection_helper.h"
 #include "net/quic/quic_crypto_client_stream_factory.h"
 #include "net/quic/quic_default_packet_writer.h"
+#include "net/quic/quic_flags.h"
 #include "net/quic/quic_http_stream.h"
 #include "net/quic/quic_protocol.h"
 #include "net/quic/quic_server_id.h"
 #include "net/socket/client_socket_factory.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #endif
 
 namespace net {
@@ skipping 513 matching lines @@
     QuicClock* clock,
     size_t max_packet_length,
     const std::string& user_agent_id,
     const QuicVersionVector& supported_versions,
     bool enable_port_selection,
     bool always_require_handshake_confirmation,
     bool disable_connection_pooling,
     int load_server_info_timeout,
     bool disable_loading_server_info_for_new_servers,
     float load_server_info_timeout_srtt_multiplier,
+    bool enable_truncated_connection_ids,
     const QuicTagVector& connection_options)
     : require_confirmation_(true),
       host_resolver_(host_resolver),
       client_socket_factory_(client_socket_factory),
       http_server_properties_(http_server_properties),
       transport_security_state_(transport_security_state),
       quic_server_info_factory_(nullptr),
       quic_crypto_client_stream_factory_(quic_crypto_client_stream_factory),
       random_generator_(random_generator),
       clock_(clock),
       max_packet_length_(max_packet_length),
       config_(InitializeQuicConfig(connection_options)),
       supported_versions_(supported_versions),
       enable_port_selection_(enable_port_selection),
       always_require_handshake_confirmation_(
           always_require_handshake_confirmation),
       disable_connection_pooling_(disable_connection_pooling),
       load_server_info_timeout_ms_(load_server_info_timeout),
       disable_loading_server_info_for_new_servers_(
           disable_loading_server_info_for_new_servers),
       load_server_info_timeout_srtt_multiplier_(
           load_server_info_timeout_srtt_multiplier),
+      enable_truncated_connection_ids_(enable_truncated_connection_ids),
       port_seed_(random_generator_->RandUint64()),
       check_persisted_supports_quic_(true),
       task_runner_(nullptr),
       weak_factory_(this) {
   DCHECK(transport_security_state_);
   crypto_config_.set_user_agent_id(user_agent_id);
   crypto_config_.AddCanonicalSuffix(".c.youtube.com");
   crypto_config_.AddCanonicalSuffix(".googlevideo.com");
   crypto_config_.SetProofVerifier(
       new ProofVerifierChromium(cert_verifier, transport_security_state));
@@ skipping 438 matching lines @@
 
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
   tracked_objects::ScopedTracker tracking_profile5(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "422516 QuicStreamFactory::CreateSession5"));
 
   InitializeCachedStateInCryptoConfig(server_id, server_info);
 
   QuicConfig config = config_;
   config.set_max_undecryptable_packets(kMaxUndecryptablePackets);
-  config.SetInitialFlowControlWindowToSend(kInitialReceiveWindowSize);
   config.SetInitialStreamFlowControlWindowToSend(kInitialReceiveWindowSize);
   config.SetInitialSessionFlowControlWindowToSend(kInitialReceiveWindowSize);
   int64 srtt = GetServerNetworkStatsSmoothedRttInMicroseconds(server_id);
   if (srtt > 0)
     config.SetInitialRoundTripTimeUsToSend(static_cast<uint32>(srtt));
+  if (FLAGS_allow_truncated_connection_ids_for_quic &&
+      enable_truncated_connection_ids_)
+    config.SetBytesForConnectionIdToSend(0);
 
   if (quic_server_info_factory_ && !server_info) {
     // TODO(vadimt): Remove ScopedTracker below once crbug.com/422516 is fixed.
     tracked_objects::ScopedTracker tracking_profile6(
         FROM_HERE_WITH_EXPLICIT_FUNCTION(
             "422516 QuicStreamFactory::CreateSession6"));
 
     // Start the disk cache loading so that we can persist the newer QUIC server
     // information and/or inform the disk cache that we have reused
     // |server_info|.
@@ skipping 153 matching lines @@
   http_server_properties_->ClearAlternateProtocol(server);
   http_server_properties_->SetAlternateProtocol(
       server, alternate.port, alternate.protocol, 1);
   DCHECK_EQ(QUIC,
             http_server_properties_->GetAlternateProtocol(server).protocol);
   DCHECK(http_server_properties_->WasAlternateProtocolRecentlyBroken(
       server));
 }
 
 }  // namespace net