Revert of Minor QUIC cleanup to combine QuicUnackedPacketMap's

net/quic/quic_sent_packet_manager.cc

Index: net/quic/quic_sent_packet_manager.cc
diff --git a/net/quic/quic_sent_packet_manager.cc b/net/quic/quic_sent_packet_manager.cc
index 0085f901fad62fd24b6f2fd99cde9e832bfbf9f9..0bc3af5ca1d8523e9fec8ff9928e135c3b36b2f6 100644
--- a/net/quic/quic_sent_packet_manager.cc
+++ b/net/quic/quic_sent_packet_manager.cc
@@ -337,7 +337,11 @@ void QuicSentPacketManager::MarkPacketRevived(
         sequence_number, delta_largest_observed);
   }
 
-  unacked_packets_.NeuterIfPendingOrRemovePacket(sequence_number);
+  if (!transmission_info.pending) {
+    unacked_packets_.RemovePacket(sequence_number);
+  } else {
+    unacked_packets_.NeuterPacket(sequence_number);
+  }
 }
 
 QuicUnackedPacketMap::const_iterator QuicSentPacketManager::MarkPacketHandled(
@@ -372,6 +376,8 @@ QuicUnackedPacketMap::const_iterator QuicSentPacketManager::MarkPacketHandled(
       unacked_packets_.GetTransmissionInfo(newest_transmission));
   while (all_transmissions_it != all_transmissions.rend()) {
     QuicPacketSequenceNumber previous_transmission = *all_transmissions_it;
+    const TransmissionInfo& transmission_info =
+        unacked_packets_.GetTransmissionInfo(previous_transmission);
     // If this packet was marked for retransmission, don't bother retransmitting
     // it anymore.
     pending_retransmissions_.erase(previous_transmission);
@@ -380,7 +386,11 @@ QuicUnackedPacketMap::const_iterator QuicSentPacketManager::MarkPacketHandled(
       // since they won't be acked now that one has been processed.
       unacked_packets_.SetNotPending(previous_transmission);
     }
-    unacked_packets_.NeuterIfPendingOrRemovePacket(previous_transmission);
+    if (!transmission_info.pending) {
+      unacked_packets_.RemovePacket(previous_transmission);
+    } else {
+      unacked_packets_.NeuterPacket(previous_transmission);
+    }
     ++all_transmissions_it;
   }
 
@@ -591,7 +601,7 @@ void QuicSentPacketManager::InvokeLossDetection(QuicTime time) {
       // unacked_packets_.   This is either the current transmission of
       // a packet whose previous transmission has been acked, or it
       // is a packet that has been TLP retransmitted.
-      unacked_packets_.NeuterIfPendingOrRemovePacket(sequence_number);
+      unacked_packets_.RemovePacket(sequence_number);
     }
   }
 }