Rename QUIC's TransmissionInfo pending to in_flight and the associated

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 ec3480a502b4d2e5e8f6816aa25db8069014647b..02634226e9d6926592abbc46a3497bc18f22b6b9 100644
--- a/net/quic/quic_unacked_packet_map.h
+++ b/net/quic/quic_unacked_packet_map.h
@@ -10,15 +10,16 @@
 
 namespace net {
 
-// Class which tracks unacked packets, including those packets which are
-// currently pending, and the relationship between packets which
-// contain the same data (via retransmissions)
+// Class which tracks unacked packets for three purposes:
+// 1) Track retransmittable data, including multiple transmissions of frames.
+// 2) Track packets and bytes in flight for congestion control.
+// 3) Track sent time of packets to provide RTT measurements from acks.
 class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
  public:
   QuicUnackedPacketMap();
   ~QuicUnackedPacketMap();
 
-  // Adds |serialized_packet| to the map.  Does not mark it pending.
+  // Adds |serialized_packet| to the map.  Does not mark it in flight.
   void AddPacket(const SerializedPacket& serialized_packet);
 
   // Called when a packet is retransmitted with a new sequence number.
@@ -35,8 +36,8 @@ class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
   void NackPacket(QuicPacketSequenceNumber sequence_number,
                   size_t min_nacks);
 
-  // Marks |sequence_number| as no longer pending.
-  void SetNotPending(QuicPacketSequenceNumber sequence_number);
+  // Marks |sequence_number| as no longer in flight.
+  void RemoveFromInFlight(QuicPacketSequenceNumber sequence_number);
 
   // Returns true if the unacked packet |sequence_number| has retransmittable
   // frames.  This will return false if the packet has been acked, if a
@@ -57,7 +58,7 @@ class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
     return largest_sent_packet_;
   }
 
-  // Returns the sum of the bytes in all pending packets.
+  // Returns the sum of bytes from all packets in flight.
   QuicByteCount bytes_in_flight() const {
     return bytes_in_flight_;
   }
@@ -67,13 +68,13 @@ class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
   QuicPacketSequenceNumber GetLeastUnackedSentPacket() const;
 
   // Sets a packet as sent with the sent time |sent_time|.  Marks the packet
-  // as pending and tracks the |bytes_sent| if |set_pending| is true.
-  // Packets marked as pending are expected to be marked as missing when they
+  // as in flight if |set_in_flight| is true.
+  // Packets marked as in flight are expected to be marked as missing when they
   // don't arrive, indicating the need for retransmission.
   void SetSent(QuicPacketSequenceNumber sequence_number,
                QuicTime sent_time,
                QuicByteCount bytes_sent,
-               bool set_pending);
+               bool set_in_flight);
 
   // Clears up to |num_to_clear| previous transmissions in order to make room
   // in the ack frame for new acks.
@@ -87,8 +88,8 @@ class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
   const_iterator begin() const { return unacked_packets_.begin(); }
   const_iterator end() const { return unacked_packets_.end(); }
 
-  // Returns true if there are unacked packets that are pending.
-  bool HasPendingPackets() const;
+  // Returns true if there are unacked packets that are in flight.
+  bool HasInFlightPackets() const;
 
   // Returns the TransmissionInfo associated with |sequence_number|, which
   // must be unacked.
@@ -98,20 +99,19 @@ class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
   // Returns the time that the last unacked packet was sent.
   QuicTime GetLastPacketSentTime() const;
 
-  // Returns the time that the first pending packet was sent.
-  QuicTime GetFirstPendingPacketSentTime() const;
+  // Returns the time that the first in flight packet was sent.
+  QuicTime GetFirstInFlightPacketSentTime() const;
 
   // Returns the number of unacked packets.
   size_t GetNumUnackedPackets() const;
 
-  // Returns true if there are multiple packet pending.
-  bool HasMultiplePendingPackets() const;
+  // Returns true if there are multiple packets in flight.
+  bool HasMultipleInFlightPackets() const;
 
   // Returns true if there are any pending crypto packets.
   bool HasPendingCryptoPackets() const;
 
   // Removes any retransmittable frames from this transmission or an associated
-
   // transmission.  It removes now useless transmissions, and disconnects any
   // other packets from other transmissions.
   void RemoveRetransmittability(QuicPacketSequenceNumber sequence_number);
@@ -124,7 +124,7 @@ class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
   void MaybeRemoveRetransmittableFrames(TransmissionInfo* transmission_info);
 
   // Returns true if the packet no longer has a purpose in the map.
-  bool IsPacketUseless(UnackedPacketMap::const_iterator it);
+  bool IsPacketUseless(UnackedPacketMap::const_iterator it) const;
 
   QuicPacketSequenceNumber largest_sent_packet_;
   QuicPacketSequenceNumber largest_observed_;
@@ -140,7 +140,7 @@ class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
   UnackedPacketMap unacked_packets_;
 
   size_t bytes_in_flight_;
-  // Number of outstanding crypto handshake packets.
+  // Number of retransmittable crypto handshake packets.
   size_t pending_crypto_packet_count_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicUnackedPacketMap);