QUIC varz to track measured and predicted bandwidth and rtt histograms

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 97569f547960a1321e944936e72aae275ef76db0..89a3b6d26a93e6ce344ab6d1fb1254cdaf3fef11 100644
--- a/net/quic/quic_sent_packet_manager.h
+++ b/net/quic/quic_sent_packet_manager.h
@@ -165,6 +165,9 @@ 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.
+  bool HasReliableBandwidthEstimate() 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.