When talking >=QUIC_VERSION_22, regularly send updated bandwidth

net/quic/quic_sent_packet_manager.h

Index: net/quic/quic_sent_packet_manager.h
diff --git a/net/quic/quic_sent_packet_manager.h b/net/quic/quic_sent_packet_manager.h
index 2e3c05d34134dc4c80320f36b2dd719f41971b69..f18b2db14ae22858f30a2734bdd842a6d974e287 100644
--- a/net/quic/quic_sent_packet_manager.h
+++ b/net/quic/quic_sent_packet_manager.h
@@ -21,6 +21,7 @@
 #include "net/quic/congestion_control/send_algorithm_interface.h"
 #include "net/quic/quic_ack_notifier_manager.h"
 #include "net/quic/quic_protocol.h"
+#include "net/quic/quic_sustained_bandwidth_recorder.h"
 #include "net/quic/quic_unacked_packet_map.h"
 
 namespace net {
@@ -197,9 +198,11 @@ class NET_EXPORT_PRIVATE QuicSentPacketManager {
   // Returns the estimated bandwidth calculated by the congestion algorithm.
   QuicBandwidth BandwidthEstimate() const;
 
-  // Returns true if the current bandwidth estimate is reliable.
+  // Returns true if the current instantaneous bandwidth estimate is reliable.
   bool HasReliableBandwidthEstimate() const;
 
+  const QuicSustainedBandwidthRecorder& SustainedBandwidthRecorder() const;
+
   // Returns the size of the current congestion window in bytes.  Note, this is
   // not the *available* window.  Some send algorithms may not use a congestion
   // window and will return 0.
@@ -377,6 +380,10 @@ class NET_EXPORT_PRIVATE QuicSentPacketManager {
   // retransmittable frames.
   bool handshake_confirmed_;
 
+  // Records bandwidth from server to client in normal operation, over periods
+  // of time with no loss events.
+  QuicSustainedBandwidthRecorder sustained_bandwidth_recorder_;
+
   DISALLOW_COPY_AND_ASSIGN(QuicSentPacketManager);
 };