Remove //net (except for Android test stuff) and sdch

net/quic/quic_connection.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_connection.h"
-
-#include <string.h>
-#include <sys/types.h>
-
-#include <algorithm>
-#include <iterator>
-#include <limits>
-#include <memory>
-#include <set>
-#include <utility>
-
-#include "base/debug/stack_trace.h"
-#include "base/format_macros.h"
-#include "base/logging.h"
-#include "base/stl_util.h"
-#include "base/strings/stringprintf.h"
-#include "net/base/net_errors.h"
-#include "net/quic/crypto/quic_decrypter.h"
-#include "net/quic/crypto/quic_encrypter.h"
-#include "net/quic/iovector.h"
-#include "net/quic/quic_bandwidth.h"
-#include "net/quic/quic_config.h"
-#include "net/quic/quic_fec_group.h"
-#include "net/quic/quic_flags.h"
-#include "net/quic/quic_packet_generator.h"
-#include "net/quic/quic_utils.h"
-
-using base::StringPiece;
-using base::StringPrintf;
-using base::hash_map;
-using base::hash_set;
-using std::list;
-using std::make_pair;
-using std::max;
-using std::min;
-using std::numeric_limits;
-using std::set;
-using std::string;
-using std::vector;
-
-namespace net {
-
-class QuicDecrypter;
-class QuicEncrypter;
-
-namespace {
-
-// The largest gap in packets we'll accept without closing the connection.
-// This will likely have to be tuned.
-const QuicPacketSequenceNumber kMaxPacketGap = 5000;
-
-// Limit the number of FEC groups to two.  If we get enough out of order packets
-// that this becomes limiting, we can revisit.
-const size_t kMaxFecGroups = 2;
-
-// Maximum number of acks received before sending an ack in response.
-const QuicPacketCount kMaxPacketsReceivedBeforeAckSend = 20;
-
-// Maximum number of tracked packets.
-const QuicPacketCount kMaxTrackedPackets = 5 * kMaxTcpCongestionWindow;
-
-bool Near(QuicPacketSequenceNumber a, QuicPacketSequenceNumber b) {
-  QuicPacketSequenceNumber delta = (a > b) ? a - b : b - a;
-  return delta <= kMaxPacketGap;
-}
-
-// An alarm that is scheduled to send an ack if a timeout occurs.
-class AckAlarm : public QuicAlarm::Delegate {
- public:
-  explicit AckAlarm(QuicConnection* connection)
-      : connection_(connection) {
-  }
-
-  QuicTime OnAlarm() override {
-    connection_->SendAck();
-    return QuicTime::Zero();
-  }
-
- private:
-  QuicConnection* connection_;
-
-  DISALLOW_COPY_AND_ASSIGN(AckAlarm);
-};
-
-// This alarm will be scheduled any time a data-bearing packet is sent out.
-// When the alarm goes off, the connection checks to see if the oldest packets
-// have been acked, and retransmit them if they have not.
-class RetransmissionAlarm : public QuicAlarm::Delegate {
- public:
-  explicit RetransmissionAlarm(QuicConnection* connection)
-      : connection_(connection) {
-  }
-
-  QuicTime OnAlarm() override {
-    connection_->OnRetransmissionTimeout();
-    return QuicTime::Zero();
-  }
-
- private:
-  QuicConnection* connection_;
-
-  DISALLOW_COPY_AND_ASSIGN(RetransmissionAlarm);
-};
-
-// An alarm that is scheduled when the sent scheduler requires a
-// a delay before sending packets and fires when the packet may be sent.
-class SendAlarm : public QuicAlarm::Delegate {
- public:
-  explicit SendAlarm(QuicConnection* connection)
-      : connection_(connection) {
-  }
-
-  QuicTime OnAlarm() override {
-    connection_->WriteIfNotBlocked();
-    // Never reschedule the alarm, since CanWrite does that.
-    return QuicTime::Zero();
-  }
-
- private:
-  QuicConnection* connection_;
-
-  DISALLOW_COPY_AND_ASSIGN(SendAlarm);
-};
-
-class TimeoutAlarm : public QuicAlarm::Delegate {
- public:
-  explicit TimeoutAlarm(QuicConnection* connection)
-      : connection_(connection) {
-  }
-
-  QuicTime OnAlarm() override {
-    connection_->CheckForTimeout();
-    // Never reschedule the alarm, since CheckForTimeout does that.
-    return QuicTime::Zero();
-  }
-
- private:
-  QuicConnection* connection_;
-
-  DISALLOW_COPY_AND_ASSIGN(TimeoutAlarm);
-};
-
-class PingAlarm : public QuicAlarm::Delegate {
- public:
-  explicit PingAlarm(QuicConnection* connection)
-      : connection_(connection) {
-  }
-
-  QuicTime OnAlarm() override {
-    connection_->SendPing();
-    return QuicTime::Zero();
-  }
-
- private:
-  QuicConnection* connection_;
-
-  DISALLOW_COPY_AND_ASSIGN(PingAlarm);
-};
-
-// This alarm may be scheduled when an FEC protected packet is sent out.
-class FecAlarm : public QuicAlarm::Delegate {
- public:
-  explicit FecAlarm(QuicPacketGenerator* packet_generator)
-      : packet_generator_(packet_generator) {}
-
-  QuicTime OnAlarm() override {
-    packet_generator_->OnFecTimeout();
-    return QuicTime::Zero();
-  }
-
- private:
-  QuicPacketGenerator* packet_generator_;
-
-  DISALLOW_COPY_AND_ASSIGN(FecAlarm);
-};
-
-}  // namespace
-
-QuicConnection::QueuedPacket::QueuedPacket(SerializedPacket packet,
-                                           EncryptionLevel level)
-    : serialized_packet(packet),
-      encryption_level(level),
-      transmission_type(NOT_RETRANSMISSION),
-      original_sequence_number(0) {
-}
-
-QuicConnection::QueuedPacket::QueuedPacket(
-    SerializedPacket packet,
-    EncryptionLevel level,
-    TransmissionType transmission_type,
-    QuicPacketSequenceNumber original_sequence_number)
-    : serialized_packet(packet),
-      encryption_level(level),
-      transmission_type(transmission_type),
-      original_sequence_number(original_sequence_number) {
-}
-
-#define ENDPOINT (is_server_ ? "Server: " : " Client: ")
-
-QuicConnection::QuicConnection(QuicConnectionId connection_id,
-                               IPEndPoint address,
-                               QuicConnectionHelperInterface* helper,
-                               const PacketWriterFactory& writer_factory,
-                               bool owns_writer,
-                               bool is_server,
-                               bool is_secure,
-                               const QuicVersionVector& supported_versions)
-    : framer_(supported_versions,
-              helper->GetClock()->ApproximateNow(),
-              is_server),
-      helper_(helper),
-      writer_(writer_factory.Create(this)),
-      owns_writer_(owns_writer),
-      encryption_level_(ENCRYPTION_NONE),
-      has_forward_secure_encrypter_(false),
-      first_required_forward_secure_packet_(0),
-      clock_(helper->GetClock()),
-      random_generator_(helper->GetRandomGenerator()),
-      connection_id_(connection_id),
-      peer_address_(address),
-      migrating_peer_port_(0),
-      last_packet_decrypted_(false),
-      last_packet_revived_(false),
-      last_size_(0),
-      last_decrypted_packet_level_(ENCRYPTION_NONE),
-      largest_seen_packet_with_ack_(0),
-      largest_seen_packet_with_stop_waiting_(0),
-      max_undecryptable_packets_(0),
-      pending_version_negotiation_packet_(false),
-      silent_close_enabled_(false),
-      received_packet_manager_(&stats_),
-      ack_queued_(false),
-      num_packets_received_since_last_ack_sent_(0),
-      stop_waiting_count_(0),
-      ack_alarm_(helper->CreateAlarm(new AckAlarm(this))),
-      retransmission_alarm_(helper->CreateAlarm(new RetransmissionAlarm(this))),
-      send_alarm_(helper->CreateAlarm(new SendAlarm(this))),
-      resume_writes_alarm_(helper->CreateAlarm(new SendAlarm(this))),
-      timeout_alarm_(helper->CreateAlarm(new TimeoutAlarm(this))),
-      ping_alarm_(helper->CreateAlarm(new PingAlarm(this))),
-      packet_generator_(connection_id_, &framer_, random_generator_, this),
-      fec_alarm_(helper->CreateAlarm(new FecAlarm(&packet_generator_))),
-      idle_network_timeout_(QuicTime::Delta::Infinite()),
-      overall_connection_timeout_(QuicTime::Delta::Infinite()),
-      time_of_last_received_packet_(clock_->ApproximateNow()),
-      time_of_last_sent_new_packet_(clock_->ApproximateNow()),
-      sequence_number_of_last_sent_packet_(0),
-      sent_packet_manager_(
-          is_server,
-          clock_,
-          &stats_,
-          FLAGS_quic_use_bbr_congestion_control ? kBBR : kCubic,
-          FLAGS_quic_use_time_loss_detection ? kTime : kNack,
-          is_secure),
-      version_negotiation_state_(START_NEGOTIATION),
-      is_server_(is_server),
-      connected_(true),
-      peer_ip_changed_(false),
-      peer_port_changed_(false),
-      self_ip_changed_(false),
-      self_port_changed_(false),
-      can_truncate_connection_ids_(true),
-      is_secure_(is_secure) {
-  DVLOG(1) << ENDPOINT << "Created connection with connection_id: "
-           << connection_id;
-  framer_.set_visitor(this);
-  framer_.set_received_entropy_calculator(&received_packet_manager_);
-  stats_.connection_creation_time = clock_->ApproximateNow();
-  sent_packet_manager_.set_network_change_visitor(this);
-  if (FLAGS_quic_small_default_packet_size && is_server_) {
-    set_max_packet_length(kDefaultServerMaxPacketSize);
-  }
-}
-
-QuicConnection::~QuicConnection() {
-  if (owns_writer_) {
-    delete writer_;
-  }
-  STLDeleteElements(&undecryptable_packets_);
-  STLDeleteValues(&group_map_);
-  for (QueuedPacketList::iterator it = queued_packets_.begin();
-       it != queued_packets_.end(); ++it) {
-    delete it->serialized_packet.retransmittable_frames;
-    delete it->serialized_packet.packet;
-  }
-}
-
-void QuicConnection::SetFromConfig(const QuicConfig& config) {
-  if (config.negotiated()) {
-    SetNetworkTimeouts(QuicTime::Delta::Infinite(),
-                       config.IdleConnectionStateLifetime());
-    if (config.SilentClose()) {
-      silent_close_enabled_ = true;
-    }
-  } else {
-    SetNetworkTimeouts(config.max_time_before_crypto_handshake(),
-                       config.max_idle_time_before_crypto_handshake());
-  }
-
-  sent_packet_manager_.SetFromConfig(config);
-  if (config.HasReceivedBytesForConnectionId() &&
-      can_truncate_connection_ids_) {
-    packet_generator_.SetConnectionIdLength(
-        config.ReceivedBytesForConnectionId());
-  }
-  max_undecryptable_packets_ = config.max_undecryptable_packets();
-}
-
-bool QuicConnection::ResumeConnectionState(
-    const CachedNetworkParameters& cached_network_params) {
-  return sent_packet_manager_.ResumeConnectionState(cached_network_params);
-}
-
-void QuicConnection::SetNumOpenStreams(size_t num_streams) {
-  sent_packet_manager_.SetNumOpenStreams(num_streams);
-}
-
-bool QuicConnection::SelectMutualVersion(
-    const QuicVersionVector& available_versions) {
-  // Try to find the highest mutual version by iterating over supported
-  // versions, starting with the highest, and breaking out of the loop once we
-  // find a matching version in the provided available_versions vector.
-  const QuicVersionVector& supported_versions = framer_.supported_versions();
-  for (size_t i = 0; i < supported_versions.size(); ++i) {
-    const QuicVersion& version = supported_versions[i];
-    if (std::find(available_versions.begin(), available_versions.end(),
-                  version) != available_versions.end()) {
-      framer_.set_version(version);
-      return true;
-    }
-  }
-
-  return false;
-}
-
-void QuicConnection::OnError(QuicFramer* framer) {
-  // Packets that we can not or have not decrypted are dropped.
-  // TODO(rch): add stats to measure this.
-  if (!connected_ || last_packet_decrypted_ == false) {
-    return;
-  }
-  SendConnectionCloseWithDetails(framer->error(), framer->detailed_error());
-}
-
-void QuicConnection::MaybeSetFecAlarm(
-    QuicPacketSequenceNumber sequence_number) {
-  if (fec_alarm_->IsSet()) {
-    return;
-  }
-  QuicTime::Delta timeout = packet_generator_.GetFecTimeout(sequence_number);
-  if (!timeout.IsInfinite()) {
-    fec_alarm_->Set(clock_->ApproximateNow().Add(timeout));
-  }
-}
-
-void QuicConnection::OnPacket() {
-  DCHECK(last_stream_frames_.empty() &&
-         last_ack_frames_.empty() &&
-         last_stop_waiting_frames_.empty() &&
-         last_rst_frames_.empty() &&
-         last_goaway_frames_.empty() &&
-         last_window_update_frames_.empty() &&
-         last_blocked_frames_.empty() &&
-         last_ping_frames_.empty() &&
-         last_close_frames_.empty());
-  last_packet_decrypted_ = false;
-  last_packet_revived_ = false;
-}
-
-void QuicConnection::OnPublicResetPacket(
-    const QuicPublicResetPacket& packet) {
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnPublicResetPacket(packet);
-  }
-  CloseConnection(QUIC_PUBLIC_RESET, true);
-
-  DVLOG(1) << ENDPOINT << "Connection " << connection_id()
-           << " closed via QUIC_PUBLIC_RESET from peer.";
-}
-
-bool QuicConnection::OnProtocolVersionMismatch(QuicVersion received_version) {
-  DVLOG(1) << ENDPOINT << "Received packet with mismatched version "
-           << received_version;
-  // TODO(satyamshekhar): Implement no server state in this mode.
-  if (!is_server_) {
-    LOG(DFATAL) << ENDPOINT << "Framer called OnProtocolVersionMismatch. "
-                << "Closing connection.";
-    CloseConnection(QUIC_INTERNAL_ERROR, false);
-    return false;
-  }
-  DCHECK_NE(version(), received_version);
-
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnProtocolVersionMismatch(received_version);
-  }
-
-  switch (version_negotiation_state_) {
-    case START_NEGOTIATION:
-      if (!framer_.IsSupportedVersion(received_version)) {
-        SendVersionNegotiationPacket();
-        version_negotiation_state_ = NEGOTIATION_IN_PROGRESS;
-        return false;
-      }
-      break;
-
-    case NEGOTIATION_IN_PROGRESS:
-      if (!framer_.IsSupportedVersion(received_version)) {
-        SendVersionNegotiationPacket();
-        return false;
-      }
-      break;
-
-    case NEGOTIATED_VERSION:
-      // Might be old packets that were sent by the client before the version
-      // was negotiated. Drop these.
-      return false;
-
-    default:
-      DCHECK(false);
-  }
-
-  version_negotiation_state_ = NEGOTIATED_VERSION;
-  visitor_->OnSuccessfulVersionNegotiation(received_version);
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnSuccessfulVersionNegotiation(received_version);
-  }
-  DVLOG(1) << ENDPOINT << "version negotiated " << received_version;
-
-  // Store the new version.
-  framer_.set_version(received_version);
-
-  // TODO(satyamshekhar): Store the sequence number of this packet and close the
-  // connection if we ever received a packet with incorrect version and whose
-  // sequence number is greater.
-  return true;
-}
-
-// Handles version negotiation for client connection.
-void QuicConnection::OnVersionNegotiationPacket(
-    const QuicVersionNegotiationPacket& packet) {
-  if (is_server_) {
-    LOG(DFATAL) << ENDPOINT << "Framer parsed VersionNegotiationPacket."
-                << " Closing connection.";
-    CloseConnection(QUIC_INTERNAL_ERROR, false);
-    return;
-  }
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnVersionNegotiationPacket(packet);
-  }
-
-  if (version_negotiation_state_ != START_NEGOTIATION) {
-    // Possibly a duplicate version negotiation packet.
-    return;
-  }
-
-  if (std::find(packet.versions.begin(),
-                packet.versions.end(), version()) !=
-      packet.versions.end()) {
-    DLOG(WARNING) << ENDPOINT << "The server already supports our version. "
-                  << "It should have accepted our connection.";
-    // Just drop the connection.
-    CloseConnection(QUIC_INVALID_VERSION_NEGOTIATION_PACKET, false);
-    return;
-  }
-
-  if (!SelectMutualVersion(packet.versions)) {
-    SendConnectionCloseWithDetails(QUIC_INVALID_VERSION,
-                                   "no common version found");
-    return;
-  }
-
-  DVLOG(1) << ENDPOINT
-           << "Negotiated version: " << QuicVersionToString(version());
-  server_supported_versions_ = packet.versions;
-  version_negotiation_state_ = NEGOTIATION_IN_PROGRESS;
-  RetransmitUnackedPackets(ALL_UNACKED_RETRANSMISSION);
-}
-
-void QuicConnection::OnRevivedPacket() {
-}
-
-bool QuicConnection::OnUnauthenticatedPublicHeader(
-    const QuicPacketPublicHeader& header) {
-  return true;
-}
-
-bool QuicConnection::OnUnauthenticatedHeader(const QuicPacketHeader& header) {
-  return true;
-}
-
-void QuicConnection::OnDecryptedPacket(EncryptionLevel level) {
-  last_decrypted_packet_level_ = level;
-  last_packet_decrypted_ = true;
-  // If this packet was foward-secure encrypted and the forward-secure encrypter
-  // is not being used, start using it.
-  if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
-      has_forward_secure_encrypter_ && level == ENCRYPTION_FORWARD_SECURE) {
-    SetDefaultEncryptionLevel(ENCRYPTION_FORWARD_SECURE);
-  }
-}
-
-bool QuicConnection::OnPacketHeader(const QuicPacketHeader& header) {
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnPacketHeader(header);
-  }
-
-  if (!ProcessValidatedPacket()) {
-    return false;
-  }
-
-  // Will be decrement below if we fall through to return true;
-  ++stats_.packets_dropped;
-
-  if (header.public_header.connection_id != connection_id_) {
-    DVLOG(1) << ENDPOINT << "Ignoring packet from unexpected ConnectionId: "
-             << header.public_header.connection_id << " instead of "
-             << connection_id_;
-    if (debug_visitor_.get() != nullptr) {
-      debug_visitor_->OnIncorrectConnectionId(
-          header.public_header.connection_id);
-    }
-    return false;
-  }
-
-  if (!Near(header.packet_sequence_number,
-            last_header_.packet_sequence_number)) {
-    DVLOG(1) << ENDPOINT << "Packet " << header.packet_sequence_number
-             << " out of bounds.  Discarding";
-    SendConnectionCloseWithDetails(QUIC_INVALID_PACKET_HEADER,
-                                   "Packet sequence number out of bounds");
-    return false;
-  }
-
-  // If this packet has already been seen, or that the sender
-  // has told us will not be retransmitted, then stop processing the packet.
-  if (!received_packet_manager_.IsAwaitingPacket(
-          header.packet_sequence_number)) {
-    DVLOG(1) << ENDPOINT << "Packet " << header.packet_sequence_number
-             << " no longer being waited for.  Discarding.";
-    if (debug_visitor_.get() != nullptr) {
-      debug_visitor_->OnDuplicatePacket(header.packet_sequence_number);
-    }
-    return false;
-  }
-
-  if (version_negotiation_state_ != NEGOTIATED_VERSION) {
-    if (is_server_) {
-      if (!header.public_header.version_flag) {
-        DLOG(WARNING) << ENDPOINT << "Packet " << header.packet_sequence_number
-                      << " without version flag before version negotiated.";
-        // Packets should have the version flag till version negotiation is
-        // done.
-        CloseConnection(QUIC_INVALID_VERSION, false);
-        return false;
-      } else {
-        DCHECK_EQ(1u, header.public_header.versions.size());
-        DCHECK_EQ(header.public_header.versions[0], version());
-        version_negotiation_state_ = NEGOTIATED_VERSION;
-        visitor_->OnSuccessfulVersionNegotiation(version());
-        if (debug_visitor_.get() != nullptr) {
-          debug_visitor_->OnSuccessfulVersionNegotiation(version());
-        }
-      }
-    } else {
-      DCHECK(!header.public_header.version_flag);
-      // If the client gets a packet without the version flag from the server
-      // it should stop sending version since the version negotiation is done.
-      packet_generator_.StopSendingVersion();
-      version_negotiation_state_ = NEGOTIATED_VERSION;
-      visitor_->OnSuccessfulVersionNegotiation(version());
-      if (debug_visitor_.get() != nullptr) {
-        debug_visitor_->OnSuccessfulVersionNegotiation(version());
-      }
-    }
-  }
-
-  DCHECK_EQ(NEGOTIATED_VERSION, version_negotiation_state_);
-
-  --stats_.packets_dropped;
-  DVLOG(1) << ENDPOINT << "Received packet header: " << header;
-  last_header_ = header;
-  DCHECK(connected_);
-  return true;
-}
-
-void QuicConnection::OnFecProtectedPayload(StringPiece payload) {
-  DCHECK_EQ(IN_FEC_GROUP, last_header_.is_in_fec_group);
-  DCHECK_NE(0u, last_header_.fec_group);
-  QuicFecGroup* group = GetFecGroup();
-  if (group != nullptr) {
-    group->Update(last_decrypted_packet_level_, last_header_, payload);
-  }
-}
-
-bool QuicConnection::OnStreamFrame(const QuicStreamFrame& frame) {
-  DCHECK(connected_);
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnStreamFrame(frame);
-  }
-  if (frame.stream_id != kCryptoStreamId &&
-      last_decrypted_packet_level_ == ENCRYPTION_NONE) {
-    DLOG(WARNING) << ENDPOINT
-                  << "Received an unencrypted data frame: closing connection";
-    SendConnectionClose(QUIC_UNENCRYPTED_STREAM_DATA);
-    return false;
-  }
-  last_stream_frames_.push_back(frame);
-  return true;
-}
-
-bool QuicConnection::OnAckFrame(const QuicAckFrame& incoming_ack) {
-  DCHECK(connected_);
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnAckFrame(incoming_ack);
-  }
-  DVLOG(1) << ENDPOINT << "OnAckFrame: " << incoming_ack;
-
-  if (last_header_.packet_sequence_number <= largest_seen_packet_with_ack_) {
-    DVLOG(1) << ENDPOINT << "Received an old ack frame: ignoring";
-    return true;
-  }
-
-  if (!ValidateAckFrame(incoming_ack)) {
-    SendConnectionClose(QUIC_INVALID_ACK_DATA);
-    return false;
-  }
-
-  last_ack_frames_.push_back(incoming_ack);
-  return connected_;
-}
-
-void QuicConnection::ProcessAckFrame(const QuicAckFrame& incoming_ack) {
-  largest_seen_packet_with_ack_ = last_header_.packet_sequence_number;
-  sent_packet_manager_.OnIncomingAck(incoming_ack,
-                                     time_of_last_received_packet_);
-  sent_entropy_manager_.ClearEntropyBefore(
-      sent_packet_manager_.least_packet_awaited_by_peer() - 1);
-  if (sent_packet_manager_.HasPendingRetransmissions()) {
-    WriteIfNotBlocked();
-  }
-
-  // Always reset the retransmission alarm when an ack comes in, since we now
-  // have a better estimate of the current rtt than when it was set.
-  QuicTime retransmission_time = sent_packet_manager_.GetRetransmissionTime();
-  retransmission_alarm_->Update(retransmission_time,
-                                QuicTime::Delta::FromMilliseconds(1));
-}
-
-void QuicConnection::ProcessStopWaitingFrame(
-    const QuicStopWaitingFrame& stop_waiting) {
-  largest_seen_packet_with_stop_waiting_ = last_header_.packet_sequence_number;
-  received_packet_manager_.UpdatePacketInformationSentByPeer(stop_waiting);
-  // Possibly close any FecGroups which are now irrelevant.
-  CloseFecGroupsBefore(stop_waiting.least_unacked + 1);
-}
-
-bool QuicConnection::OnStopWaitingFrame(const QuicStopWaitingFrame& frame) {
-  DCHECK(connected_);
-
-  if (last_header_.packet_sequence_number <=
-      largest_seen_packet_with_stop_waiting_) {
-    DVLOG(1) << ENDPOINT << "Received an old stop waiting frame: ignoring";
-    return true;
-  }
-
-  if (!ValidateStopWaitingFrame(frame)) {
-    SendConnectionClose(QUIC_INVALID_STOP_WAITING_DATA);
-    return false;
-  }
-
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnStopWaitingFrame(frame);
-  }
-
-  last_stop_waiting_frames_.push_back(frame);
-  return connected_;
-}
-
-bool QuicConnection::OnPingFrame(const QuicPingFrame& frame) {
-  DCHECK(connected_);
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnPingFrame(frame);
-  }
-  last_ping_frames_.push_back(frame);
-  return true;
-}
-
-bool QuicConnection::ValidateAckFrame(const QuicAckFrame& incoming_ack) {
-  if (incoming_ack.largest_observed > packet_generator_.sequence_number()) {
-    DLOG(ERROR) << ENDPOINT << "Peer's observed unsent packet:"
-                << incoming_ack.largest_observed << " vs "
-                << packet_generator_.sequence_number();
-    // We got an error for data we have not sent.  Error out.
-    return false;
-  }
-
-  if (incoming_ack.largest_observed < sent_packet_manager_.largest_observed()) {
-    DLOG(ERROR) << ENDPOINT << "Peer's largest_observed packet decreased:"
-                << incoming_ack.largest_observed << " vs "
-                << sent_packet_manager_.largest_observed();
-    // A new ack has a diminished largest_observed value.  Error out.
-    // If this was an old packet, we wouldn't even have checked.
-    return false;
-  }
-
-  if (!incoming_ack.missing_packets.empty() &&
-      *incoming_ack.missing_packets.rbegin() > incoming_ack.largest_observed) {
-    DLOG(ERROR) << ENDPOINT << "Peer sent missing packet: "
-                << *incoming_ack.missing_packets.rbegin()
-                << " which is greater than largest observed: "
-                << incoming_ack.largest_observed;
-    return false;
-  }
-
-  if (!incoming_ack.missing_packets.empty() &&
-      *incoming_ack.missing_packets.begin() <
-      sent_packet_manager_.least_packet_awaited_by_peer()) {
-    DLOG(ERROR) << ENDPOINT << "Peer sent missing packet: "
-                << *incoming_ack.missing_packets.begin()
-                << " which is smaller than least_packet_awaited_by_peer_: "
-                << sent_packet_manager_.least_packet_awaited_by_peer();
-    return false;
-  }
-
-  if (!sent_entropy_manager_.IsValidEntropy(
-          incoming_ack.largest_observed,
-          incoming_ack.missing_packets,
-          incoming_ack.entropy_hash)) {
-    DLOG(ERROR) << ENDPOINT << "Peer sent invalid entropy.";
-    return false;
-  }
-
-  for (SequenceNumberSet::const_iterator iter =
-           incoming_ack.revived_packets.begin();
-       iter != incoming_ack.revived_packets.end(); ++iter) {
-    if (!ContainsKey(incoming_ack.missing_packets, *iter)) {
-      DLOG(ERROR) << ENDPOINT
-                  << "Peer specified revived packet which was not missing.";
-      return false;
-    }
-  }
-  return true;
-}
-
-bool QuicConnection::ValidateStopWaitingFrame(
-    const QuicStopWaitingFrame& stop_waiting) {
-  if (stop_waiting.least_unacked <
-      received_packet_manager_.peer_least_packet_awaiting_ack()) {
-    DLOG(ERROR) << ENDPOINT << "Peer's sent low least_unacked: "
-                << stop_waiting.least_unacked << " vs "
-                << received_packet_manager_.peer_least_packet_awaiting_ack();
-    // We never process old ack frames, so this number should only increase.
-    return false;
-  }
-
-  if (stop_waiting.least_unacked >
-      last_header_.packet_sequence_number) {
-    DLOG(ERROR) << ENDPOINT << "Peer sent least_unacked:"
-                << stop_waiting.least_unacked
-                << " greater than the enclosing packet sequence number:"
-                << last_header_.packet_sequence_number;
-    return false;
-  }
-
-  return true;
-}
-
-void QuicConnection::OnFecData(const QuicFecData& fec) {
-  DCHECK_EQ(IN_FEC_GROUP, last_header_.is_in_fec_group);
-  DCHECK_NE(0u, last_header_.fec_group);
-  QuicFecGroup* group = GetFecGroup();
-  if (group != nullptr) {
-    group->UpdateFec(last_decrypted_packet_level_,
-                     last_header_.packet_sequence_number, fec);
-  }
-}
-
-bool QuicConnection::OnRstStreamFrame(const QuicRstStreamFrame& frame) {
-  DCHECK(connected_);
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnRstStreamFrame(frame);
-  }
-  DVLOG(1) << ENDPOINT << "Stream reset with error "
-           << QuicUtils::StreamErrorToString(frame.error_code);
-  last_rst_frames_.push_back(frame);
-  return connected_;
-}
-
-bool QuicConnection::OnConnectionCloseFrame(
-    const QuicConnectionCloseFrame& frame) {
-  DCHECK(connected_);
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnConnectionCloseFrame(frame);
-  }
-  DVLOG(1) << ENDPOINT << "Connection " << connection_id()
-           << " closed with error "
-           << QuicUtils::ErrorToString(frame.error_code)
-           << " " << frame.error_details;
-  last_close_frames_.push_back(frame);
-  return connected_;
-}
-
-bool QuicConnection::OnGoAwayFrame(const QuicGoAwayFrame& frame) {
-  DCHECK(connected_);
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnGoAwayFrame(frame);
-  }
-  DVLOG(1) << ENDPOINT << "Go away received with error "
-           << QuicUtils::ErrorToString(frame.error_code)
-           << " and reason:" << frame.reason_phrase;
-  last_goaway_frames_.push_back(frame);
-  return connected_;
-}
-
-bool QuicConnection::OnWindowUpdateFrame(const QuicWindowUpdateFrame& frame) {
-  DCHECK(connected_);
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnWindowUpdateFrame(frame);
-  }
-  DVLOG(1) << ENDPOINT << "WindowUpdate received for stream: "
-           << frame.stream_id << " with byte offset: " << frame.byte_offset;
-  last_window_update_frames_.push_back(frame);
-  return connected_;
-}
-
-bool QuicConnection::OnBlockedFrame(const QuicBlockedFrame& frame) {
-  DCHECK(connected_);
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnBlockedFrame(frame);
-  }
-  DVLOG(1) << ENDPOINT << "Blocked frame received for stream: "
-           << frame.stream_id;
-  last_blocked_frames_.push_back(frame);
-  return connected_;
-}
-
-void QuicConnection::OnPacketComplete() {
-  // Don't do anything if this packet closed the connection.
-  if (!connected_) {
-    ClearLastFrames();
-    return;
-  }
-
-  DVLOG(1) << ENDPOINT << (last_packet_revived_ ? "Revived" : "Got")
-           << " packet " << last_header_.packet_sequence_number
-           << " with " << last_stream_frames_.size()<< " stream frames "
-           << last_ack_frames_.size() << " acks, "
-           << last_stop_waiting_frames_.size() << " stop_waiting, "
-           << last_rst_frames_.size() << " rsts, "
-           << last_goaway_frames_.size() << " goaways, "
-           << last_window_update_frames_.size() << " window updates, "
-           << last_blocked_frames_.size() << " blocked, "
-           << last_ping_frames_.size() << " pings, "
-           << last_close_frames_.size() << " closes, "
-           << "for " << last_header_.public_header.connection_id;
-
-  ++num_packets_received_since_last_ack_sent_;
-
-  // Call MaybeQueueAck() before recording the received packet, since we want
-  // to trigger an ack if the newly received packet was previously missing.
-  MaybeQueueAck();
-
-  // Record received or revived packet to populate ack info correctly before
-  // processing stream frames, since the processing may result in a response
-  // packet with a bundled ack.
-  if (last_packet_revived_) {
-    received_packet_manager_.RecordPacketRevived(
-        last_header_.packet_sequence_number);
-  } else {
-    received_packet_manager_.RecordPacketReceived(
-        last_size_, last_header_, time_of_last_received_packet_);
-  }
-
-  if (!last_stream_frames_.empty()) {
-    visitor_->OnStreamFrames(last_stream_frames_);
-  }
-
-  for (size_t i = 0; i < last_stream_frames_.size(); ++i) {
-    stats_.stream_bytes_received +=
-        last_stream_frames_[i].data.TotalBufferSize();
-  }
-
-  // Process window updates, blocked, stream resets, acks, then congestion
-  // feedback.
-  if (!last_window_update_frames_.empty()) {
-    visitor_->OnWindowUpdateFrames(last_window_update_frames_);
-  }
-  if (!last_blocked_frames_.empty()) {
-    visitor_->OnBlockedFrames(last_blocked_frames_);
-  }
-  for (size_t i = 0; i < last_goaway_frames_.size(); ++i) {
-    visitor_->OnGoAway(last_goaway_frames_[i]);
-  }
-  for (size_t i = 0; i < last_rst_frames_.size(); ++i) {
-    visitor_->OnRstStream(last_rst_frames_[i]);
-  }
-  for (size_t i = 0; i < last_ack_frames_.size(); ++i) {
-    ProcessAckFrame(last_ack_frames_[i]);
-  }
-  for (size_t i = 0; i < last_stop_waiting_frames_.size(); ++i) {
-    ProcessStopWaitingFrame(last_stop_waiting_frames_[i]);
-  }
-  if (!last_close_frames_.empty()) {
-    CloseConnection(last_close_frames_[0].error_code, true);
-    DCHECK(!connected_);
-  }
-
-  // If there are new missing packets to report, send an ack immediately.
-  if (received_packet_manager_.HasNewMissingPackets()) {
-    ack_queued_ = true;
-    ack_alarm_->Cancel();
-  }
-
-  UpdateStopWaitingCount();
-  ClearLastFrames();
-  MaybeCloseIfTooManyOutstandingPackets();
-}
-
-void QuicConnection::MaybeQueueAck() {
-  // If the incoming packet was missing, send an ack immediately.
-  ack_queued_ = received_packet_manager_.IsMissing(
-      last_header_.packet_sequence_number);
-
-  if (!ack_queued_ && ShouldLastPacketInstigateAck()) {
-    if (ack_alarm_->IsSet()) {
-      ack_queued_ = true;
-    } else {
-      // Send an ack much more quickly for crypto handshake packets.
-      QuicTime::Delta delayed_ack_time = sent_packet_manager_.DelayedAckTime();
-      ack_alarm_->Set(clock_->ApproximateNow().Add(delayed_ack_time));
-      DVLOG(1) << "Ack timer set; next packet or timer will trigger ACK.";
-    }
-  }
-
-  if (ack_queued_) {
-    ack_alarm_->Cancel();
-  }
-}
-
-void QuicConnection::ClearLastFrames() {
-  last_stream_frames_.clear();
-  last_ack_frames_.clear();
-  last_stop_waiting_frames_.clear();
-  last_rst_frames_.clear();
-  last_goaway_frames_.clear();
-  last_window_update_frames_.clear();
-  last_blocked_frames_.clear();
-  last_ping_frames_.clear();
-  last_close_frames_.clear();
-}
-
-void QuicConnection::MaybeCloseIfTooManyOutstandingPackets() {
-  // This occurs if we don't discard old packets we've sent fast enough.
-  // It's possible largest observed is less than least unacked.
-  if (sent_packet_manager_.largest_observed() >
-          (sent_packet_manager_.GetLeastUnacked() + kMaxTrackedPackets)) {
-    SendConnectionCloseWithDetails(
-        QUIC_TOO_MANY_OUTSTANDING_SENT_PACKETS,
-        StringPrintf("More than %" PRIu64 " outstanding.", kMaxTrackedPackets));
-  }
-  // This occurs if there are received packet gaps and the peer does not raise
-  // the least unacked fast enough.
-  if (received_packet_manager_.NumTrackedPackets() > kMaxTrackedPackets) {
-    SendConnectionCloseWithDetails(
-        QUIC_TOO_MANY_OUTSTANDING_RECEIVED_PACKETS,
-        StringPrintf("More than %" PRIu64 " outstanding.", kMaxTrackedPackets));
-  }
-}
-
-void QuicConnection::PopulateAckFrame(QuicAckFrame* ack) {
-  received_packet_manager_.UpdateReceivedPacketInfo(ack,
-                                                    clock_->ApproximateNow());
-}
-
-void QuicConnection::PopulateStopWaitingFrame(
-    QuicStopWaitingFrame* stop_waiting) {
-  stop_waiting->least_unacked = GetLeastUnacked();
-  stop_waiting->entropy_hash = sent_entropy_manager_.GetCumulativeEntropy(
-      stop_waiting->least_unacked - 1);
-}
-
-bool QuicConnection::ShouldLastPacketInstigateAck() const {
-  if (!last_stream_frames_.empty() ||
-      !last_goaway_frames_.empty() ||
-      !last_rst_frames_.empty() ||
-      !last_window_update_frames_.empty() ||
-      !last_blocked_frames_.empty() ||
-      !last_ping_frames_.empty()) {
-    return true;
-  }
-
-  if (!last_ack_frames_.empty() && last_ack_frames_.back().is_truncated) {
-    return true;
-  }
-  // Always send an ack every 20 packets in order to allow the peer to discard
-  // information from the SentPacketManager and provide an RTT measurement.
-  if (num_packets_received_since_last_ack_sent_ >=
-          kMaxPacketsReceivedBeforeAckSend) {
-    return true;
-  }
-  return false;
-}
-
-void QuicConnection::UpdateStopWaitingCount() {
-  if (last_ack_frames_.empty()) {
-    return;
-  }
-
-  // If the peer is still waiting for a packet that we are no longer planning to
-  // send, send an ack to raise the high water mark.
-  if (!last_ack_frames_.back().missing_packets.empty() &&
-      GetLeastUnacked() > *last_ack_frames_.back().missing_packets.begin()) {
-    ++stop_waiting_count_;
-  } else {
-    stop_waiting_count_ = 0;
-  }
-}
-
-QuicPacketSequenceNumber QuicConnection::GetLeastUnacked() const {
-  return sent_packet_manager_.GetLeastUnacked();
-}
-
-void QuicConnection::MaybeSendInResponseToPacket() {
-  if (!connected_) {
-    return;
-  }
-  ScopedPacketBundler bundler(this, ack_queued_ ? SEND_ACK : NO_ACK);
-
-  // Now that we have received an ack, we might be able to send packets which
-  // are queued locally, or drain streams which are blocked.
-  if (CanWrite(HAS_RETRANSMITTABLE_DATA)) {
-    OnCanWrite();
-  }
-}
-
-void QuicConnection::SendVersionNegotiationPacket() {
-  // TODO(alyssar): implement zero server state negotiation.
-  pending_version_negotiation_packet_ = true;
-  if (writer_->IsWriteBlocked()) {
-    visitor_->OnWriteBlocked();
-    return;
-  }
-  DVLOG(1) << ENDPOINT << "Sending version negotiation packet: {"
-           << QuicVersionVectorToString(framer_.supported_versions()) << "}";
-  scoped_ptr<QuicEncryptedPacket> version_packet(
-      packet_generator_.SerializeVersionNegotiationPacket(
-          framer_.supported_versions()));
-  WriteResult result = writer_->WritePacket(
-      version_packet->data(), version_packet->length(),
-      self_address().address(), peer_address());
-
-  if (result.status == WRITE_STATUS_ERROR) {
-    // We can't send an error as the socket is presumably borked.
-    CloseConnection(QUIC_PACKET_WRITE_ERROR, false);
-    return;
-  }
-  if (result.status == WRITE_STATUS_BLOCKED) {
-    visitor_->OnWriteBlocked();
-    if (writer_->IsWriteBlockedDataBuffered()) {
-      pending_version_negotiation_packet_ = false;
-    }
-    return;
-  }
-
-  pending_version_negotiation_packet_ = false;
-}
-
-QuicConsumedData QuicConnection::SendStreamData(
-    QuicStreamId id,
-    const IOVector& data,
-    QuicStreamOffset offset,
-    bool fin,
-    FecProtection fec_protection,
-    QuicAckNotifier::DelegateInterface* delegate) {
-  if (!fin && data.Empty()) {
-    LOG(DFATAL) << "Attempt to send empty stream frame";
-    return QuicConsumedData(0, false);
-  }
-
-  // Opportunistically bundle an ack with every outgoing packet.
-  // Particularly, we want to bundle with handshake packets since we don't know
-  // which decrypter will be used on an ack packet following a handshake
-  // packet (a handshake packet from client to server could result in a REJ or a
-  // SHLO from the server, leading to two different decrypters at the server.)
-  //
-  // TODO(jri): Note that ConsumeData may cause a response packet to be sent.
-  // We may end up sending stale ack information if there are undecryptable
-  // packets hanging around and/or there are revivable packets which may get
-  // handled after this packet is sent. Change ScopedPacketBundler to do the
-  // right thing: check ack_queued_, and then check undecryptable packets and
-  // also if there is possibility of revival. Only bundle an ack if there's no
-  // processing left that may cause received_info_ to change.
-  ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
-  return packet_generator_.ConsumeData(id, data, offset, fin, fec_protection,
-                                       delegate);
-}
-
-void QuicConnection::SendRstStream(QuicStreamId id,
-                                   QuicRstStreamErrorCode error,
-                                   QuicStreamOffset bytes_written) {
-  // Opportunistically bundle an ack with this outgoing packet.
-  ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
-  packet_generator_.AddControlFrame(QuicFrame(new QuicRstStreamFrame(
-      id, AdjustErrorForVersion(error, version()), bytes_written)));
-}
-
-void QuicConnection::SendWindowUpdate(QuicStreamId id,
-                                      QuicStreamOffset byte_offset) {
-  // Opportunistically bundle an ack with this outgoing packet.
-  ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
-  packet_generator_.AddControlFrame(
-      QuicFrame(new QuicWindowUpdateFrame(id, byte_offset)));
-}
-
-void QuicConnection::SendBlocked(QuicStreamId id) {
-  // Opportunistically bundle an ack with this outgoing packet.
-  ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
-  packet_generator_.AddControlFrame(QuicFrame(new QuicBlockedFrame(id)));
-}
-
-const QuicConnectionStats& QuicConnection::GetStats() {
-  const RttStats* rtt_stats = sent_packet_manager_.GetRttStats();
-
-  // Update rtt and estimated bandwidth.
-  QuicTime::Delta min_rtt = rtt_stats->min_rtt();
-  if (min_rtt.IsZero()) {
-    // If min RTT has not been set, use initial RTT instead.
-    min_rtt = QuicTime::Delta::FromMicroseconds(rtt_stats->initial_rtt_us());
-  }
-  stats_.min_rtt_us = min_rtt.ToMicroseconds();
-
-  QuicTime::Delta srtt = rtt_stats->smoothed_rtt();
-  if (srtt.IsZero()) {
-    // If SRTT has not been set, use initial RTT instead.
-    srtt = QuicTime::Delta::FromMicroseconds(rtt_stats->initial_rtt_us());
-  }
-  stats_.srtt_us = srtt.ToMicroseconds();
-
-  stats_.estimated_bandwidth = sent_packet_manager_.BandwidthEstimate();
-  stats_.max_packet_size = packet_generator_.max_packet_length();
-  return stats_;
-}
-
-void QuicConnection::ProcessUdpPacket(const IPEndPoint& self_address,
-                                      const IPEndPoint& peer_address,
-                                      const QuicEncryptedPacket& packet) {
-  if (!connected_) {
-    return;
-  }
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnPacketReceived(self_address, peer_address, packet);
-  }
-  last_size_ = packet.length();
-
-  CheckForAddressMigration(self_address, peer_address);
-
-  stats_.bytes_received += packet.length();
-  ++stats_.packets_received;
-
-  if (!framer_.ProcessPacket(packet)) {
-    // If we are unable to decrypt this packet, it might be
-    // because the CHLO or SHLO packet was lost.
-    if (framer_.error() == QUIC_DECRYPTION_FAILURE) {
-      if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
-          undecryptable_packets_.size() < max_undecryptable_packets_) {
-        QueueUndecryptablePacket(packet);
-      } else if (debug_visitor_.get() != nullptr) {
-        debug_visitor_->OnUndecryptablePacket();
-      }
-    }
-    DVLOG(1) << ENDPOINT << "Unable to process packet.  Last packet processed: "
-             << last_header_.packet_sequence_number;
-    return;
-  }
-
-  ++stats_.packets_processed;
-  MaybeProcessUndecryptablePackets();
-  MaybeProcessRevivedPacket();
-  MaybeSendInResponseToPacket();
-  SetPingAlarm();
-}
-
-void QuicConnection::CheckForAddressMigration(
-    const IPEndPoint& self_address, const IPEndPoint& peer_address) {
-  peer_ip_changed_ = false;
-  peer_port_changed_ = false;
-  self_ip_changed_ = false;
-  self_port_changed_ = false;
-
-  if (peer_address_.address().empty()) {
-    peer_address_ = peer_address;
-  }
-  if (self_address_.address().empty()) {
-    self_address_ = self_address;
-  }
-
-  if (!peer_address.address().empty() && !peer_address_.address().empty()) {
-    peer_ip_changed_ = (peer_address.address() != peer_address_.address());
-    peer_port_changed_ = (peer_address.port() != peer_address_.port());
-
-    // Store in case we want to migrate connection in ProcessValidatedPacket.
-    migrating_peer_port_ = peer_address.port();
-  }
-
-  if (!self_address.address().empty() && !self_address_.address().empty()) {
-    self_ip_changed_ = (self_address.address() != self_address_.address());
-    self_port_changed_ = (self_address.port() != self_address_.port());
-  }
-}
-
-void QuicConnection::OnCanWrite() {
-  DCHECK(!writer_->IsWriteBlocked());
-
-  WriteQueuedPackets();
-  WritePendingRetransmissions();
-
-  // Sending queued packets may have caused the socket to become write blocked,
-  // or the congestion manager to prohibit sending.  If we've sent everything
-  // we had queued and we're still not blocked, let the visitor know it can
-  // write more.
-  if (!CanWrite(HAS_RETRANSMITTABLE_DATA)) {
-    return;
-  }
-
-  { // Limit the scope of the bundler. ACK inclusion happens elsewhere.
-    ScopedPacketBundler bundler(this, NO_ACK);
-    visitor_->OnCanWrite();
-  }
-
-  // After the visitor writes, it may have caused the socket to become write
-  // blocked or the congestion manager to prohibit sending, so check again.
-  if (visitor_->WillingAndAbleToWrite() &&
-      !resume_writes_alarm_->IsSet() &&
-      CanWrite(HAS_RETRANSMITTABLE_DATA)) {
-    // We're not write blocked, but some stream didn't write out all of its
-    // bytes. Register for 'immediate' resumption so we'll keep writing after
-    // other connections and events have had a chance to use the thread.
-    resume_writes_alarm_->Set(clock_->ApproximateNow());
-  }
-}
-
-void QuicConnection::WriteIfNotBlocked() {
-  if (!writer_->IsWriteBlocked()) {
-    OnCanWrite();
-  }
-}
-
-bool QuicConnection::ProcessValidatedPacket() {
-  if (peer_ip_changed_ || self_ip_changed_ || self_port_changed_) {
-    SendConnectionCloseWithDetails(
-        QUIC_ERROR_MIGRATING_ADDRESS,
-        "Neither IP address migration, nor self port migration are supported.");
-    return false;
-  }
-
-  // Peer port migration is supported, do it now if port has changed.
-  if (peer_port_changed_) {
-    DVLOG(1) << ENDPOINT << "Peer's port changed from "
-             << peer_address_.port() << " to " << migrating_peer_port_
-             << ", migrating connection.";
-    peer_address_ = IPEndPoint(peer_address_.address(), migrating_peer_port_);
-  }
-
-  time_of_last_received_packet_ = clock_->Now();
-  DVLOG(1) << ENDPOINT << "time of last received packet: "
-           << time_of_last_received_packet_.ToDebuggingValue();
-
-  if (is_server_ && encryption_level_ == ENCRYPTION_NONE &&
-      last_size_ > packet_generator_.max_packet_length()) {
-    set_max_packet_length(last_size_);
-  }
-  return true;
-}
-
-void QuicConnection::WriteQueuedPackets() {
-  DCHECK(!writer_->IsWriteBlocked());
-
-  if (pending_version_negotiation_packet_) {
-    SendVersionNegotiationPacket();
-  }
-
-  QueuedPacketList::iterator packet_iterator = queued_packets_.begin();
-  while (packet_iterator != queued_packets_.end() &&
-         WritePacket(&(*packet_iterator))) {
-    packet_iterator = queued_packets_.erase(packet_iterator);
-  }
-}
-
-void QuicConnection::WritePendingRetransmissions() {
-  // Keep writing as long as there's a pending retransmission which can be
-  // written.
-  while (sent_packet_manager_.HasPendingRetransmissions()) {
-    const QuicSentPacketManager::PendingRetransmission pending =
-        sent_packet_manager_.NextPendingRetransmission();
-    if (!CanWrite(HAS_RETRANSMITTABLE_DATA)) {
-      break;
-    }
-
-    // Re-packetize the frames with a new sequence number for retransmission.
-    // Retransmitted data packets do not use FEC, even when it's enabled.
-    // Retransmitted packets use the same sequence number length as the
-    // original.
-    // Flush the packet generator before making a new packet.
-    // TODO(ianswett): Implement ReserializeAllFrames as a separate path that
-    // does not require the creator to be flushed.
-    packet_generator_.FlushAllQueuedFrames();
-    SerializedPacket serialized_packet = packet_generator_.ReserializeAllFrames(
-        pending.retransmittable_frames, pending.sequence_number_length);
-    if (serialized_packet.packet == nullptr) {
-      // We failed to serialize the packet, so close the connection.
-      // CloseConnection does not send close packet, so no infinite loop here.
-      CloseConnection(QUIC_ENCRYPTION_FAILURE, false);
-      return;
-    }
-
-    DVLOG(1) << ENDPOINT << "Retransmitting " << pending.sequence_number
-             << " as " << serialized_packet.sequence_number;
-    SendOrQueuePacket(
-        QueuedPacket(serialized_packet,
-                     pending.retransmittable_frames.encryption_level(),
-                     pending.transmission_type,
-                     pending.sequence_number));
-  }
-}
-
-void QuicConnection::RetransmitUnackedPackets(
-    TransmissionType retransmission_type) {
-  sent_packet_manager_.RetransmitUnackedPackets(retransmission_type);
-
-  WriteIfNotBlocked();
-}
-
-void QuicConnection::NeuterUnencryptedPackets() {
-  sent_packet_manager_.NeuterUnencryptedPackets();
-  // This may have changed the retransmission timer, so re-arm it.
-  QuicTime retransmission_time = sent_packet_manager_.GetRetransmissionTime();
-  retransmission_alarm_->Update(retransmission_time,
-                                QuicTime::Delta::FromMilliseconds(1));
-}
-
-bool QuicConnection::ShouldGeneratePacket(
-    TransmissionType transmission_type,
-    HasRetransmittableData retransmittable,
-    IsHandshake handshake) {
-  // We should serialize handshake packets immediately to ensure that they
-  // end up sent at the right encryption level.
-  if (handshake == IS_HANDSHAKE) {
-    return true;
-  }
-
-  return CanWrite(retransmittable);
-}
-
-bool QuicConnection::CanWrite(HasRetransmittableData retransmittable) {
-  if (!connected_) {
-    return false;
-  }
-
-  if (writer_->IsWriteBlocked()) {
-    visitor_->OnWriteBlocked();
-    return false;
-  }
-
-  QuicTime now = clock_->Now();
-  QuicTime::Delta delay = sent_packet_manager_.TimeUntilSend(
-      now, retransmittable);
-  if (delay.IsInfinite()) {
-    send_alarm_->Cancel();
-    return false;
-  }
-
-  // If the scheduler requires a delay, then we can not send this packet now.
-  if (!delay.IsZero()) {
-    send_alarm_->Update(now.Add(delay), QuicTime::Delta::FromMilliseconds(1));
-    DVLOG(1) << ENDPOINT << "Delaying sending " << delay.ToMilliseconds()
-             << "ms";
-    return false;
-  }
-  send_alarm_->Cancel();
-  return true;
-}
-
-bool QuicConnection::WritePacket(QueuedPacket* packet) {
-  if (!WritePacketInner(packet)) {
-    return false;
-  }
-  delete packet->serialized_packet.retransmittable_frames;
-  delete packet->serialized_packet.packet;
-  packet->serialized_packet.retransmittable_frames = nullptr;
-  packet->serialized_packet.packet = nullptr;
-  return true;
-}
-
-bool QuicConnection::WritePacketInner(QueuedPacket* packet) {
-  if (ShouldDiscardPacket(*packet)) {
-    ++stats_.packets_discarded;
-    return true;
-  }
-  // Connection close packets are encrypted and saved, so don't exit early.
-  const bool is_connection_close = IsConnectionClose(*packet);
-  if (writer_->IsWriteBlocked() && !is_connection_close) {
-    return false;
-  }
-
-  QuicPacketSequenceNumber sequence_number =
-      packet->serialized_packet.sequence_number;
-  DCHECK_LE(sequence_number_of_last_sent_packet_, sequence_number);
-  sequence_number_of_last_sent_packet_ = sequence_number;
-
-  QuicEncryptedPacket* encrypted = packet->serialized_packet.packet;
-  // Connection close packets are eventually owned by TimeWaitListManager.
-  // Others are deleted at the end of this call.
-  if (is_connection_close) {
-    DCHECK(connection_close_packet_.get() == nullptr);
-    connection_close_packet_.reset(encrypted);
-    packet->serialized_packet.packet = nullptr;
-    // This assures we won't try to write *forced* packets when blocked.
-    // Return true to stop processing.
-    if (writer_->IsWriteBlocked()) {
-      visitor_->OnWriteBlocked();
-      return true;
-    }
-  }
-
-  if (!FLAGS_quic_allow_oversized_packets_for_test) {
-    DCHECK_LE(encrypted->length(), kMaxPacketSize);
-  }
-  DCHECK_LE(encrypted->length(), packet_generator_.max_packet_length());
-  DVLOG(1) << ENDPOINT << "Sending packet " << sequence_number << " : "
-           << (packet->serialized_packet.is_fec_packet
-                   ? "FEC "
-                   : (IsRetransmittable(*packet) == HAS_RETRANSMITTABLE_DATA
-                          ? "data bearing "
-                          : " ack only ")) << ", encryption level: "
-           << QuicUtils::EncryptionLevelToString(packet->encryption_level)
-           << ", encrypted length:" << encrypted->length();
-  DVLOG(2) << ENDPOINT << "packet(" << sequence_number << "): " << std::endl
-           << QuicUtils::StringToHexASCIIDump(encrypted->AsStringPiece());
-
-  QuicTime packet_send_time = QuicTime::Zero();
-  if (FLAGS_quic_record_send_time_before_write) {
-    // Measure the RTT from before the write begins to avoid underestimating the
-    // min_rtt_, especially in cases where the thread blocks or gets swapped out
-    // during the WritePacket below.
-    packet_send_time = clock_->Now();
-  }
-  WriteResult result = writer_->WritePacket(encrypted->data(),
-                                            encrypted->length(),
-                                            self_address().address(),
-                                            peer_address());
-  if (result.error_code == ERR_IO_PENDING) {
-    DCHECK_EQ(WRITE_STATUS_BLOCKED, result.status);
-  }
-
-  if (result.status == WRITE_STATUS_BLOCKED) {
-    visitor_->OnWriteBlocked();
-    // If the socket buffers the the data, then the packet should not
-    // be queued and sent again, which would result in an unnecessary
-    // duplicate packet being sent.  The helper must call OnCanWrite
-    // when the write completes, and OnWriteError if an error occurs.
-    if (!writer_->IsWriteBlockedDataBuffered()) {
-      return false;
-    }
-  }
-  if (!FLAGS_quic_record_send_time_before_write) {
-    packet_send_time = clock_->Now();
-  }
-  if (!packet_send_time.IsInitialized()) {
-    // TODO(jokulik): This is only needed because of the two code paths for
-    // initializing packet_send_time.  Once "quic_record_send_time_before_write"
-    // is deprecated, this check can be removed.
-    LOG(DFATAL) << "The packet send time should never be zero. "
-                << "This is a programming bug, please report it.";
-  }
-  if (result.status != WRITE_STATUS_ERROR && debug_visitor_.get() != nullptr) {
-    // Pass the write result to the visitor.
-    debug_visitor_->OnPacketSent(packet->serialized_packet,
-                                 packet->original_sequence_number,
-                                 packet->encryption_level,
-                                 packet->transmission_type,
-                                 *encrypted,
-                                 packet_send_time);
-  }
-  if (packet->transmission_type == NOT_RETRANSMISSION) {
-    time_of_last_sent_new_packet_ = packet_send_time;
-  }
-  SetPingAlarm();
-  MaybeSetFecAlarm(sequence_number);
-  DVLOG(1) << ENDPOINT << "time "
-           << (FLAGS_quic_record_send_time_before_write ?
-               "we began writing " : "we finished writing ")
-           << "last sent packet: "
-           << packet_send_time.ToDebuggingValue();
-
-  // TODO(ianswett): Change the sequence number length and other packet creator
-  // options by a more explicit API than setting a struct value directly,
-  // perhaps via the NetworkChangeVisitor.
-  packet_generator_.UpdateSequenceNumberLength(
-      sent_packet_manager_.least_packet_awaited_by_peer(),
-      sent_packet_manager_.EstimateMaxPacketsInFlight(max_packet_length()));
-
-  bool reset_retransmission_alarm = sent_packet_manager_.OnPacketSent(
-      &packet->serialized_packet,
-      packet->original_sequence_number,
-      packet_send_time,
-      encrypted->length(),
-      packet->transmission_type,
-      IsRetransmittable(*packet));
-
-  if (reset_retransmission_alarm || !retransmission_alarm_->IsSet()) {
-    retransmission_alarm_->Update(sent_packet_manager_.GetRetransmissionTime(),
-                                  QuicTime::Delta::FromMilliseconds(1));
-  }
-
-  stats_.bytes_sent += result.bytes_written;
-  ++stats_.packets_sent;
-  if (packet->transmission_type != NOT_RETRANSMISSION) {
-    stats_.bytes_retransmitted += result.bytes_written;
-    ++stats_.packets_retransmitted;
-  }
-
-  if (result.status == WRITE_STATUS_ERROR) {
-    OnWriteError(result.error_code);
-    DLOG(ERROR) << ENDPOINT << "failed writing " << encrypted->length()
-                << "bytes "
-                << " from host " << self_address().ToStringWithoutPort()
-                << " to address " << peer_address().ToString();
-    return false;
-  }
-
-  return true;
-}
-
-bool QuicConnection::ShouldDiscardPacket(const QueuedPacket& packet) {
-  if (!connected_) {
-    DVLOG(1) << ENDPOINT
-             << "Not sending packet as connection is disconnected.";
-    return true;
-  }
-
-  QuicPacketSequenceNumber sequence_number =
-      packet.serialized_packet.sequence_number;
-  if (encryption_level_ == ENCRYPTION_FORWARD_SECURE &&
-      packet.encryption_level == ENCRYPTION_NONE) {
-    // Drop packets that are NULL encrypted since the peer won't accept them
-    // anymore.
-    DVLOG(1) << ENDPOINT << "Dropping NULL encrypted packet: "
-             << sequence_number << " since the connection is forward secure.";
-    return true;
-  }
-
-  // If a retransmission has been acked before sending, don't send it.
-  // This occurs if a packet gets serialized, queued, then discarded.
-  if (packet.transmission_type != NOT_RETRANSMISSION &&
-      (!sent_packet_manager_.IsUnacked(packet.original_sequence_number) ||
-       !sent_packet_manager_.HasRetransmittableFrames(
-           packet.original_sequence_number))) {
-    DVLOG(1) << ENDPOINT << "Dropping unacked packet: " << sequence_number
-             << " A previous transmission was acked while write blocked.";
-    return true;
-  }
-
-  return false;
-}
-
-void QuicConnection::OnWriteError(int error_code) {
-  DVLOG(1) << ENDPOINT << "Write failed with error: " << error_code
-           << " (" << ErrorToString(error_code) << ")";
-  // We can't send an error as the socket is presumably borked.
-  CloseConnection(QUIC_PACKET_WRITE_ERROR, false);
-}
-
-void QuicConnection::OnSerializedPacket(
-    const SerializedPacket& serialized_packet) {
-  if (serialized_packet.packet == nullptr) {
-    // We failed to serialize the packet, so close the connection.
-    // CloseConnection does not send close packet, so no infinite loop here.
-    CloseConnection(QUIC_ENCRYPTION_FAILURE, false);
-    return;
-  }
-  if (serialized_packet.retransmittable_frames) {
-    serialized_packet.retransmittable_frames->
-        set_encryption_level(encryption_level_);
-
-    sent_packet_manager_.OnSerializedPacket(serialized_packet);
-  }
-  if (serialized_packet.is_fec_packet && fec_alarm_->IsSet()) {
-    // If an FEC packet is serialized with the FEC alarm set, cancel the alarm.
-    fec_alarm_->Cancel();
-  }
-  SendOrQueuePacket(QueuedPacket(serialized_packet, encryption_level_));
-}
-
-void QuicConnection::OnCongestionWindowChange() {
-  packet_generator_.OnCongestionWindowChange(
-      sent_packet_manager_.EstimateMaxPacketsInFlight(max_packet_length()));
-  visitor_->OnCongestionWindowChange(clock_->ApproximateNow());
-}
-
-void QuicConnection::OnRttChange() {
-  // Uses the connection's smoothed RTT. If zero, uses initial_rtt.
-  QuicTime::Delta rtt = sent_packet_manager_.GetRttStats()->smoothed_rtt();
-  if (rtt.IsZero()) {
-    rtt = QuicTime::Delta::FromMicroseconds(
-        sent_packet_manager_.GetRttStats()->initial_rtt_us());
-  }
-  packet_generator_.OnRttChange(rtt);
-}
-
-void QuicConnection::OnHandshakeComplete() {
-  sent_packet_manager_.SetHandshakeConfirmed();
-  // The client should immediately ack the SHLO to confirm the handshake is
-  // complete with the server.
-  if (!is_server_ && !ack_queued_) {
-    ack_alarm_->Cancel();
-    ack_alarm_->Set(clock_->ApproximateNow());
-  }
-}
-
-void QuicConnection::SendOrQueuePacket(QueuedPacket packet) {
-  // The caller of this function is responsible for checking CanWrite().
-  if (packet.serialized_packet.packet == nullptr) {
-    LOG(DFATAL)
-        << "packet.serialized_packet.packet == nullptr in to SendOrQueuePacket";
-    return;
-  }
-
-  sent_entropy_manager_.RecordPacketEntropyHash(
-      packet.serialized_packet.sequence_number,
-      packet.serialized_packet.entropy_hash);
-  if (!WritePacket(&packet)) {
-    queued_packets_.push_back(packet);
-  }
-
-  // If a forward-secure encrypter is available but is not being used and the
-  // next sequence number is the first packet which requires
-  // forward security, start using the forward-secure encrypter.
-  if (encryption_level_ != ENCRYPTION_FORWARD_SECURE &&
-      has_forward_secure_encrypter_ &&
-      packet.serialized_packet.sequence_number >=
-          first_required_forward_secure_packet_ - 1) {
-    SetDefaultEncryptionLevel(ENCRYPTION_FORWARD_SECURE);
-  }
-}
-
-void QuicConnection::SendPing() {
-  if (retransmission_alarm_->IsSet()) {
-    return;
-  }
-  packet_generator_.AddControlFrame(QuicFrame(new QuicPingFrame));
-}
-
-void QuicConnection::SendAck() {
-  ack_alarm_->Cancel();
-  stop_waiting_count_ = 0;
-  num_packets_received_since_last_ack_sent_ = 0;
-
-  packet_generator_.SetShouldSendAck(true);
-}
-
-void QuicConnection::OnRetransmissionTimeout() {
-  if (!sent_packet_manager_.HasUnackedPackets()) {
-    return;
-  }
-
-  sent_packet_manager_.OnRetransmissionTimeout();
-  WriteIfNotBlocked();
-
-  // A write failure can result in the connection being closed, don't attempt to
-  // write further packets, or to set alarms.
-  if (!connected_) {
-    return;
-  }
-
-  // In the TLP case, the SentPacketManager gives the connection the opportunity
-  // to send new data before retransmitting.
-  if (sent_packet_manager_.MaybeRetransmitTailLossProbe()) {
-    // Send the pending retransmission now that it's been queued.
-    WriteIfNotBlocked();
-  }
-
-  // Ensure the retransmission alarm is always set if there are unacked packets
-  // and nothing waiting to be sent.
-  if (!HasQueuedData() && !retransmission_alarm_->IsSet()) {
-    QuicTime rto_timeout = sent_packet_manager_.GetRetransmissionTime();
-    if (rto_timeout.IsInitialized()) {
-      retransmission_alarm_->Set(rto_timeout);
-    }
-  }
-}
-
-void QuicConnection::SetEncrypter(EncryptionLevel level,
-                                  QuicEncrypter* encrypter) {
-  framer_.SetEncrypter(level, encrypter);
-  if (level == ENCRYPTION_FORWARD_SECURE) {
-    has_forward_secure_encrypter_ = true;
-    first_required_forward_secure_packet_ =
-        sequence_number_of_last_sent_packet_ +
-        // 3 times the current congestion window (in slow start) should cover
-        // about two full round trips worth of packets, which should be
-        // sufficient.
-        3 * sent_packet_manager_.EstimateMaxPacketsInFlight(
-            max_packet_length());
-  }
-}
-
-const QuicEncrypter* QuicConnection::encrypter(EncryptionLevel level) const {
-  return framer_.encrypter(level);
-}
-
-void QuicConnection::SetDefaultEncryptionLevel(EncryptionLevel level) {
-  encryption_level_ = level;
-  packet_generator_.set_encryption_level(level);
-}
-
-void QuicConnection::SetDecrypter(QuicDecrypter* decrypter,
-                                  EncryptionLevel level) {
-  framer_.SetDecrypter(decrypter, level);
-}
-
-void QuicConnection::SetAlternativeDecrypter(QuicDecrypter* decrypter,
-                                             EncryptionLevel level,
-                                             bool latch_once_used) {
-  framer_.SetAlternativeDecrypter(decrypter, level, latch_once_used);
-}
-
-const QuicDecrypter* QuicConnection::decrypter() const {
-  return framer_.decrypter();
-}
-
-const QuicDecrypter* QuicConnection::alternative_decrypter() const {
-  return framer_.alternative_decrypter();
-}
-
-void QuicConnection::QueueUndecryptablePacket(
-    const QuicEncryptedPacket& packet) {
-  DVLOG(1) << ENDPOINT << "Queueing undecryptable packet.";
-  undecryptable_packets_.push_back(packet.Clone());
-}
-
-void QuicConnection::MaybeProcessUndecryptablePackets() {
-  if (undecryptable_packets_.empty() || encryption_level_ == ENCRYPTION_NONE) {
-    return;
-  }
-
-  while (connected_ && !undecryptable_packets_.empty()) {
-    DVLOG(1) << ENDPOINT << "Attempting to process undecryptable packet";
-    QuicEncryptedPacket* packet = undecryptable_packets_.front();
-    if (!framer_.ProcessPacket(*packet) &&
-        framer_.error() == QUIC_DECRYPTION_FAILURE) {
-      DVLOG(1) << ENDPOINT << "Unable to process undecryptable packet...";
-      break;
-    }
-    DVLOG(1) << ENDPOINT << "Processed undecryptable packet!";
-    ++stats_.packets_processed;
-    delete packet;
-    undecryptable_packets_.pop_front();
-  }
-
-  // Once forward secure encryption is in use, there will be no
-  // new keys installed and hence any undecryptable packets will
-  // never be able to be decrypted.
-  if (encryption_level_ == ENCRYPTION_FORWARD_SECURE) {
-    if (debug_visitor_.get() != nullptr) {
-      // TODO(rtenneti): perhaps more efficient to pass the number of
-      // undecryptable packets as the argument to OnUndecryptablePacket so that
-      // we just need to call OnUndecryptablePacket once?
-      for (size_t i = 0; i < undecryptable_packets_.size(); ++i) {
-        debug_visitor_->OnUndecryptablePacket();
-      }
-    }
-    STLDeleteElements(&undecryptable_packets_);
-  }
-}
-
-void QuicConnection::MaybeProcessRevivedPacket() {
-  QuicFecGroup* group = GetFecGroup();
-  if (!connected_ || group == nullptr || !group->CanRevive()) {
-    return;
-  }
-  QuicPacketHeader revived_header;
-  char revived_payload[kMaxPacketSize];
-  size_t len = group->Revive(&revived_header, revived_payload, kMaxPacketSize);
-  revived_header.public_header.connection_id = connection_id_;
-  revived_header.public_header.connection_id_length =
-      last_header_.public_header.connection_id_length;
-  revived_header.public_header.version_flag = false;
-  revived_header.public_header.reset_flag = false;
-  revived_header.public_header.sequence_number_length =
-      last_header_.public_header.sequence_number_length;
-  revived_header.fec_flag = false;
-  revived_header.is_in_fec_group = NOT_IN_FEC_GROUP;
-  revived_header.fec_group = 0;
-  group_map_.erase(last_header_.fec_group);
-  last_decrypted_packet_level_ = group->effective_encryption_level();
-  DCHECK_LT(last_decrypted_packet_level_, NUM_ENCRYPTION_LEVELS);
-  delete group;
-
-  last_packet_revived_ = true;
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnRevivedPacket(revived_header,
-                                    StringPiece(revived_payload, len));
-  }
-
-  ++stats_.packets_revived;
-  framer_.ProcessRevivedPacket(&revived_header,
-                               StringPiece(revived_payload, len));
-}
-
-QuicFecGroup* QuicConnection::GetFecGroup() {
-  QuicFecGroupNumber fec_group_num = last_header_.fec_group;
-  if (fec_group_num == 0) {
-    return nullptr;
-  }
-  if (!ContainsKey(group_map_, fec_group_num)) {
-    if (group_map_.size() >= kMaxFecGroups) {  // Too many groups
-      if (fec_group_num < group_map_.begin()->first) {
-        // The group being requested is a group we've seen before and deleted.
-        // Don't recreate it.
-        return nullptr;
-      }
-      // Clear the lowest group number.
-      delete group_map_.begin()->second;
-      group_map_.erase(group_map_.begin());
-    }
-    group_map_[fec_group_num] = new QuicFecGroup();
-  }
-  return group_map_[fec_group_num];
-}
-
-void QuicConnection::SendConnectionClose(QuicErrorCode error) {
-  SendConnectionCloseWithDetails(error, string());
-}
-
-void QuicConnection::SendConnectionCloseWithDetails(QuicErrorCode error,
-                                                    const string& details) {
-  // If we're write blocked, WritePacket() will not send, but will capture the
-  // serialized packet.
-  SendConnectionClosePacket(error, details);
-  if (connected_) {
-    // It's possible that while sending the connection close packet, we get a
-    // socket error and disconnect right then and there.  Avoid a double
-    // disconnect in that case.
-    CloseConnection(error, false);
-  }
-}
-
-void QuicConnection::SendConnectionClosePacket(QuicErrorCode error,
-                                               const string& details) {
-  DVLOG(1) << ENDPOINT << "Force closing " << connection_id()
-           << " with error " << QuicUtils::ErrorToString(error)
-           << " (" << error << ") " << details;
-  // Don't send explicit connection close packets for timeouts.
-  // This is particularly important on mobile, where connections are short.
-  if (silent_close_enabled_ &&
-      error == QuicErrorCode::QUIC_CONNECTION_TIMED_OUT) {
-    return;
-  }
-  ScopedPacketBundler ack_bundler(this, SEND_ACK);
-  QuicConnectionCloseFrame* frame = new QuicConnectionCloseFrame();
-  frame->error_code = error;
-  frame->error_details = details;
-  packet_generator_.AddControlFrame(QuicFrame(frame));
-  packet_generator_.FlushAllQueuedFrames();
-}
-
-void QuicConnection::CloseConnection(QuicErrorCode error, bool from_peer) {
-  if (!connected_) {
-    DLOG(DFATAL) << "Error: attempt to close an already closed connection"
-                 << base::debug::StackTrace().ToString();
-    return;
-  }
-  connected_ = false;
-  if (debug_visitor_.get() != nullptr) {
-    debug_visitor_->OnConnectionClosed(error, from_peer);
-  }
-  visitor_->OnConnectionClosed(error, from_peer);
-  // Cancel the alarms so they don't trigger any action now that the
-  // connection is closed.
-  ack_alarm_->Cancel();
-  ping_alarm_->Cancel();
-  fec_alarm_->Cancel();
-  resume_writes_alarm_->Cancel();
-  retransmission_alarm_->Cancel();
-  send_alarm_->Cancel();
-  timeout_alarm_->Cancel();
-}
-
-void QuicConnection::SendGoAway(QuicErrorCode error,
-                                QuicStreamId last_good_stream_id,
-                                const string& reason) {
-  DVLOG(1) << ENDPOINT << "Going away with error "
-           << QuicUtils::ErrorToString(error)
-           << " (" << error << ")";
-
-  // Opportunistically bundle an ack with this outgoing packet.
-  ScopedPacketBundler ack_bundler(this, BUNDLE_PENDING_ACK);
-  packet_generator_.AddControlFrame(
-      QuicFrame(new QuicGoAwayFrame(error, last_good_stream_id, reason)));
-}
-
-void QuicConnection::CloseFecGroupsBefore(
-    QuicPacketSequenceNumber sequence_number) {
-  FecGroupMap::iterator it = group_map_.begin();
-  while (it != group_map_.end()) {
-    // If this is the current group or the group doesn't protect this packet
-    // we can ignore it.
-    if (last_header_.fec_group == it->first ||
-        !it->second->ProtectsPacketsBefore(sequence_number)) {
-      ++it;
-      continue;
-    }
-    QuicFecGroup* fec_group = it->second;
-    DCHECK(!fec_group->CanRevive());
-    FecGroupMap::iterator next = it;
-    ++next;
-    group_map_.erase(it);
-    delete fec_group;
-    it = next;
-  }
-}
-
-QuicByteCount QuicConnection::max_packet_length() const {
-  return packet_generator_.max_packet_length();
-}
-
-void QuicConnection::set_max_packet_length(QuicByteCount length) {
-  return packet_generator_.set_max_packet_length(length);
-}
-
-bool QuicConnection::HasQueuedData() const {
-  return pending_version_negotiation_packet_ ||
-      !queued_packets_.empty() || packet_generator_.HasQueuedFrames();
-}
-
-bool QuicConnection::CanWriteStreamData() {
-  // Don't write stream data if there are negotiation or queued data packets
-  // to send. Otherwise, continue and bundle as many frames as possible.
-  if (pending_version_negotiation_packet_ || !queued_packets_.empty()) {
-    return false;
-  }
-
-  IsHandshake pending_handshake = visitor_->HasPendingHandshake() ?
-      IS_HANDSHAKE : NOT_HANDSHAKE;
-  // Sending queued packets may have caused the socket to become write blocked,
-  // or the congestion manager to prohibit sending.  If we've sent everything
-  // we had queued and we're still not blocked, let the visitor know it can
-  // write more.
-  return ShouldGeneratePacket(NOT_RETRANSMISSION, HAS_RETRANSMITTABLE_DATA,
-                              pending_handshake);
-}
-
-void QuicConnection::SetNetworkTimeouts(QuicTime::Delta overall_timeout,
-                                        QuicTime::Delta idle_timeout) {
-  LOG_IF(DFATAL, idle_timeout > overall_timeout)
-      << "idle_timeout:" << idle_timeout.ToMilliseconds()
-      << " overall_timeout:" << overall_timeout.ToMilliseconds();
-  // Adjust the idle timeout on client and server to prevent clients from
-  // sending requests to servers which have already closed the connection.
-  if (is_server_) {
-    idle_timeout = idle_timeout.Add(QuicTime::Delta::FromSeconds(3));
-  } else if (idle_timeout > QuicTime::Delta::FromSeconds(1)) {
-    idle_timeout = idle_timeout.Subtract(QuicTime::Delta::FromSeconds(1));
-  }
-  overall_connection_timeout_ = overall_timeout;
-  idle_network_timeout_ = idle_timeout;
-
-  SetTimeoutAlarm();
-}
-
-void QuicConnection::CheckForTimeout() {
-  QuicTime now = clock_->ApproximateNow();
-  QuicTime time_of_last_packet = max(time_of_last_received_packet_,
-                                     time_of_last_sent_new_packet_);
-
-  // |delta| can be < 0 as |now| is approximate time but |time_of_last_packet|
-  // is accurate time. However, this should not change the behavior of
-  // timeout handling.
-  QuicTime::Delta idle_duration = now.Subtract(time_of_last_packet);
-  DVLOG(1) << ENDPOINT << "last packet "
-           << time_of_last_packet.ToDebuggingValue()
-           << " now:" << now.ToDebuggingValue()
-           << " idle_duration:" << idle_duration.ToMicroseconds()
-           << " idle_network_timeout: "
-           << idle_network_timeout_.ToMicroseconds();
-  if (idle_duration >= idle_network_timeout_) {
-    DVLOG(1) << ENDPOINT << "Connection timedout due to no network activity.";
-    SendConnectionClose(QUIC_CONNECTION_TIMED_OUT);
-    return;
-  }
-
-  if (!overall_connection_timeout_.IsInfinite()) {
-    QuicTime::Delta connected_duration =
-        now.Subtract(stats_.connection_creation_time);
-    DVLOG(1) << ENDPOINT << "connection time: "
-             << connected_duration.ToMicroseconds() << " overall timeout: "
-             << overall_connection_timeout_.ToMicroseconds();
-    if (connected_duration >= overall_connection_timeout_) {
-      DVLOG(1) << ENDPOINT <<
-          "Connection timedout due to overall connection timeout.";
-      SendConnectionClose(QUIC_CONNECTION_OVERALL_TIMED_OUT);
-      return;
-    }
-  }
-
-  SetTimeoutAlarm();
-}
-
-void QuicConnection::SetTimeoutAlarm() {
-  QuicTime time_of_last_packet = max(time_of_last_received_packet_,
-                                     time_of_last_sent_new_packet_);
-
-  QuicTime deadline = time_of_last_packet.Add(idle_network_timeout_);
-  if (!overall_connection_timeout_.IsInfinite()) {
-    deadline = min(deadline,
-                   stats_.connection_creation_time.Add(
-                       overall_connection_timeout_));
-  }
-
-  timeout_alarm_->Cancel();
-  timeout_alarm_->Set(deadline);
-}
-
-void QuicConnection::SetPingAlarm() {
-  if (is_server_) {
-    // Only clients send pings.
-    return;
-  }
-  if (!visitor_->HasOpenDataStreams()) {
-    ping_alarm_->Cancel();
-    // Don't send a ping unless there are open streams.
-    return;
-  }
-  QuicTime::Delta ping_timeout = QuicTime::Delta::FromSeconds(kPingTimeoutSecs);
-  ping_alarm_->Update(clock_->ApproximateNow().Add(ping_timeout),
-                      QuicTime::Delta::FromSeconds(1));
-}
-
-QuicConnection::ScopedPacketBundler::ScopedPacketBundler(
-    QuicConnection* connection,
-    AckBundling send_ack)
-    : connection_(connection),
-      already_in_batch_mode_(connection != nullptr &&
-                             connection->packet_generator_.InBatchMode()) {
-  if (connection_ == nullptr) {
-    return;
-  }
-  // Move generator into batch mode. If caller wants us to include an ack,
-  // check the delayed-ack timer to see if there's ack info to be sent.
-  if (!already_in_batch_mode_) {
-    DVLOG(1) << "Entering Batch Mode.";
-    connection_->packet_generator_.StartBatchOperations();
-  }
-  // Bundle an ack if the alarm is set or with every second packet if we need to
-  // raise the peer's least unacked.
-  bool ack_pending =
-      connection_->ack_alarm_->IsSet() || connection_->stop_waiting_count_ > 1;
-  if (send_ack == SEND_ACK || (send_ack == BUNDLE_PENDING_ACK && ack_pending)) {
-    DVLOG(1) << "Bundling ack with outgoing packet.";
-    connection_->SendAck();
-  }
-}
-
-QuicConnection::ScopedPacketBundler::~ScopedPacketBundler() {
-  if (connection_ == nullptr) {
-    return;
-  }
-  // If we changed the generator's batch state, restore original batch state.
-  if (!already_in_batch_mode_) {
-    DVLOG(1) << "Leaving Batch Mode.";
-    connection_->packet_generator_.FinishBatchOperations();
-  }
-  DCHECK_EQ(already_in_batch_mode_,
-            connection_->packet_generator_.InBatchMode());
-}
-
-HasRetransmittableData QuicConnection::IsRetransmittable(
-    const QueuedPacket& packet) {
-  // Retransmitted packets retransmittable frames are owned by the unacked
-  // packet map, but are not present in the serialized packet.
-  if (packet.transmission_type != NOT_RETRANSMISSION ||
-      packet.serialized_packet.retransmittable_frames != nullptr) {
-    return HAS_RETRANSMITTABLE_DATA;
-  } else {
-    return NO_RETRANSMITTABLE_DATA;
-  }
-}
-
-bool QuicConnection::IsConnectionClose(const QueuedPacket& packet) {
-  const RetransmittableFrames* retransmittable_frames =
-      packet.serialized_packet.retransmittable_frames;
-  if (retransmittable_frames == nullptr) {
-    return false;
-  }
-  for (const QuicFrame& frame : retransmittable_frames->frames()) {
-    if (frame.type == CONNECTION_CLOSE_FRAME) {
-      return true;
-    }
-  }
-  return false;
-}
-
-}  // namespace net