Add an IncreaseLargestObserved to QuicUnackedPacketMap to remove the rtt

net/quic/quic_unacked_packet_map.h

Index: net/quic/quic_unacked_packet_map.h
diff --git a/net/quic/quic_unacked_packet_map.h b/net/quic/quic_unacked_packet_map.h
index 610639c68d865488cedf94ceff8c24f73b0261cf..ec3480a502b4d2e5e8f6816aa25db8069014647b 100644
--- a/net/quic/quic_unacked_packet_map.h
+++ b/net/quic/quic_unacked_packet_map.h
@@ -111,29 +111,23 @@ class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
   bool HasPendingCryptoPackets() const;
 
   // Removes any retransmittable frames from this transmission or an associated
-  // transmission.  It removes any nnon-pending transmissions less than or
-  // equal to |largest_observed|, and disconnects any other packets from other
-  // transmissions.
-  // TODO(ianswett): Remove largest_observed_ once the map tracks whether a
-  // transmission is useful for RTT purposes internally.
-  void RemoveRetransmittability(QuicPacketSequenceNumber sequence_number,
-                                QuicPacketSequenceNumber largest_observed_);
-
-  // Removes an entry from the unacked packet map which is not pending, has
-  // no retransmittable frames, and no associated transmissions.
-  // TODO(ianswett): Remove or make this method private once the map tracks
-  // the three reasons for tracking a packet correctly.
-  void RemoveRttOnlyPacket(QuicPacketSequenceNumber sequence_number);
-
-  // Returns true if the packet's only purpose is to measure RTT.  It must not
-  // be pending, have retransmittable frames, or be linked to transmissions
-  // with retransmittable frames.
-  static bool IsForRttOnly(const TransmissionInfo& transmission_info);
+
+  // transmission.  It removes now useless transmissions, and disconnects any
+  // other packets from other transmissions.
+  void RemoveRetransmittability(QuicPacketSequenceNumber sequence_number);
+
+  // Increases the largest observed.  Any packets less or equal to
+  // |largest_acked_packet| are discarded if they are only for the RTT purposes.
+  void IncreaseLargestObserved(QuicPacketSequenceNumber largest_observed);
 
  private:
   void MaybeRemoveRetransmittableFrames(TransmissionInfo* transmission_info);
 
+  // Returns true if the packet no longer has a purpose in the map.
+  bool IsPacketUseless(UnackedPacketMap::const_iterator it);
+
   QuicPacketSequenceNumber largest_sent_packet_;
+  QuicPacketSequenceNumber largest_observed_;
 
   // Newly serialized retransmittable and fec packets are added to this map,
   // which contains owning pointers to any contained frames.  If a packet is