Fix memory corruption from SetMaxPacingRate by inlining PacingSender.

net/quic/core/congestion_control/pacing_sender.h

 // Copyright (c) 2013 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.
 //
 // A send algorithm that adds pacing on top of an another send algorithm.
 // It uses the underlying sender's pacing rate to schedule packets.
 // It also takes into consideration the expected granularity of the underlying
 // alarm to ensure that alarms are not set too aggressively, and err towards
 // sending packets too early instead of too late.
 
 #ifndef NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_
 #define NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 
 #include "base/macros.h"
 #include "net/quic/core/congestion_control/send_algorithm_interface.h"
 #include "net/quic/core/quic_bandwidth.h"
 #include "net/quic/core/quic_config.h"
 #include "net/quic/core/quic_protocol.h"
 #include "net/quic/core/quic_time.h"
 
 namespace net {
 
-class NET_EXPORT_PRIVATE PacingSender : public SendAlgorithmInterface {
+class NET_EXPORT_PRIVATE PacingSender {
  public:
-  // Create a PacingSender to wrap the specified sender.  |alarm_granularity|
-  // indicates to the pacer to send that far into the future, since it should
-  // not expect a callback before that time delta.  |initial_packet_burst| is
-  // the number of packets sent without pacing after quiescence.
-  PacingSender(SendAlgorithmInterface* sender,
-               QuicTime::Delta alarm_granularity,
-               uint32_t initial_packet_burst);
-  ~PacingSender() override;
+  PacingSender();
+  ~PacingSender();
 
-  void SetMaxPacingRate(QuicBandwidth max_pacing_rate);
+  // Sets the underlying sender. Does not take ownership of |sender|. |sender|
+  // must not be null. This must be called before any of the
+  // SendAlgorithmInterface wrapper methods are called.
+  void set_sender(SendAlgorithmInterface* sender);
 
-  // SendAlgorithmInterface methods.
-  void SetFromConfig(const QuicConfig& config,
-                     Perspective perspective) override;
-  void ResumeConnectionState(
-      const CachedNetworkParameters& cached_network_params,
-      bool max_bandwidth_resumption) override;
-  void SetNumEmulatedConnections(int num_connections) override;
-  void OnCongestionEvent(bool rtt_updated,
-                         QuicByteCount bytes_in_flight,
-                         const CongestionVector& acked_packets,
-                         const CongestionVector& lost_packets) override;
+  void set_max_pacing_rate(QuicBandwidth max_pacing_rate) {
+    max_pacing_rate_ = max_pacing_rate;
+  }
+
+  void OnCongestionEvent(
+      bool rtt_updated,
+      QuicByteCount bytes_in_flight,
+      const SendAlgorithmInterface::CongestionVector& acked_packets,
+      const SendAlgorithmInterface::CongestionVector& lost_packets);
   bool OnPacketSent(QuicTime sent_time,
                     QuicByteCount bytes_in_flight,
                     QuicPacketNumber packet_number,
                     QuicByteCount bytes,
-                    HasRetransmittableData is_retransmittable) override;
-  void OnRetransmissionTimeout(bool packets_retransmitted) override;
-  void OnConnectionMigration() override;
+                    HasRetransmittableData is_retransmittable);
   QuicTime::Delta TimeUntilSend(QuicTime now,
-                                QuicByteCount bytes_in_flight) const override;
-  QuicBandwidth PacingRate(QuicByteCount bytes_in_flight) const override;
-  QuicBandwidth BandwidthEstimate() const override;
-  QuicTime::Delta RetransmissionDelay() const override;
-  QuicByteCount GetCongestionWindow() const override;
-  bool InSlowStart() const override;
-  bool InRecovery() const override;
-  QuicByteCount GetSlowStartThreshold() const override;
-  CongestionControlType GetCongestionControlType() const override;
-  std::string GetDebugState() const override;
-  void OnApplicationLimited(QuicByteCount bytes_in_flight) override;
-  // End implementation of SendAlgorithmInterface.
+                                QuicByteCount bytes_in_flight) const;
+  QuicBandwidth PacingRate(QuicByteCount bytes_in_flight) const;
 
  private:
-  std::unique_ptr<SendAlgorithmInterface> sender_;  // Underlying sender.
-  // The estimated system alarm granularity.
-  const QuicTime::Delta alarm_granularity_;
-  // Configured maximum size of the burst coming out of quiescence.  The burst
-  // is never larger than the current CWND in packets.
-  const uint32_t initial_packet_burst_;
+  // Underlying sender. Not owned.
+  SendAlgorithmInterface* sender_;
   // If not QuicBandidth::Zero, the maximum rate the PacingSender will use.
   QuicBandwidth max_pacing_rate_;
 
   // Number of unpaced packets to be sent before packets are delayed.
   uint32_t burst_tokens_;
   // Send time of the last packet considered delayed.
   QuicTime last_delayed_packet_sent_time_;
   QuicTime ideal_next_packet_send_time_;  // When can the next packet be sent.
   mutable bool was_last_send_delayed_;  // True when the last send was delayed.
 
   DISALLOW_COPY_AND_ASSIGN(PacingSender);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CONGESTION_CONTROL_PACING_SENDER_H_