Simplify QuicSentPacketManager MarkPacketHandled to take an iterator

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 0c6c407b404ab0b644e90642e05f6a1691173e20..d65e361dccd9ea862fefa26741052f6ec511141a 100644
--- a/net/quic/quic_sent_packet_manager.h
+++ b/net/quic/quic_sent_packet_manager.h
@@ -227,11 +227,11 @@ class NET_EXPORT_PRIVATE QuicSentPacketManager {
   void MarkPacketRevived(QuicPacketSequenceNumber sequence_number,
                          QuicTime::Delta delta_largest_observed);
 
-  // Marks |sequence_number| as being fully handled, either due to receipt
-  // by the peer, or having been discarded as indecipherable.  Returns an
-  // iterator to the next remaining unacked packet.
+  // Removes the retransmittability and pending properties from the packet at
+  // |it| due to receipt by the peer.  Returns an iterator to the next remaining
+  // unacked packet.
   QuicUnackedPacketMap::const_iterator MarkPacketHandled(
-      QuicPacketSequenceNumber sequence_number,
+      QuicUnackedPacketMap::const_iterator it,
       QuicTime::Delta delta_largest_observed);
 
   // Request that |sequence_number| be retransmitted after the other pending