Change TransmissionInfo's all_transmissions SequenceNumberSet* to

net/quic/quic_unacked_packet_map.cc

Index: net/quic/quic_unacked_packet_map.cc
diff --git a/net/quic/quic_unacked_packet_map.cc b/net/quic/quic_unacked_packet_map.cc
index 330e74aac7b416ab5fc4b7b0e06e84c1c9619057..0640c29940c1a5d0d5415c39575b1fb450fd70a1 100644
--- a/net/quic/quic_unacked_packet_map.cc
+++ b/net/quic/quic_unacked_packet_map.cc
@@ -27,7 +27,8 @@ QuicUnackedPacketMap::~QuicUnackedPacketMap() {
        it != unacked_packets_.end(); ++it, ++index) {
     delete it->retransmittable_frames;
     // Only delete all_transmissions once, for the newest packet.
-    if (index == *it->all_transmissions->rbegin()) {
+    if (it->all_transmissions != NULL &&
+        index == *it->all_transmissions->rbegin()) {
       delete it->all_transmissions;
     }
   }
@@ -41,7 +42,6 @@ void QuicUnackedPacketMap::AddPacket(
             serialized_packet.sequence_number);
   unacked_packets_.push_back(
       TransmissionInfo(serialized_packet.retransmittable_frames,
-                       serialized_packet.sequence_number,
                        serialized_packet.sequence_number_length));
   if (serialized_packet.retransmittable_frames != NULL &&
       serialized_packet.retransmittable_frames->HasCryptoHandshake()
@@ -82,7 +82,7 @@ void QuicUnackedPacketMap::OnRetransmittedPacket(
   transmission_info->retransmittable_frames = NULL;
   // Only keep one transmission older than largest observed, because only the
   // most recent is expected to possibly be a spurious retransmission.
-  if (transmission_info->all_transmissions->size() > 1 &&
+  if (transmission_info->all_transmissions != NULL &&
       *(++transmission_info->all_transmissions->begin()) < largest_observed_) {
     QuicPacketSequenceNumber old_transmission =
         *transmission_info->all_transmissions->begin();
@@ -90,15 +90,18 @@ void QuicUnackedPacketMap::OnRetransmittedPacket(
         &unacked_packets_[old_transmission - least_unacked_];
     // Don't remove old packets if they're still in flight.
     if (!old_info->in_flight) {
-      transmission_info->all_transmissions->erase(old_transmission);
+      old_info->all_transmissions->pop_front();
       // This will cause the packet be removed in RemoveObsoletePackets.
-      old_info->all_transmissions = new SequenceNumberSet();
-      old_info->all_transmissions->insert(old_transmission);
+      old_info->all_transmissions = NULL;
     }
   }
+  if (transmission_info->all_transmissions == NULL) {
+    transmission_info->all_transmissions = new SequenceNumberList();
+    transmission_info->all_transmissions->push_back(old_sequence_number);
+  }
+  transmission_info->all_transmissions->push_back(new_sequence_number);
   unacked_packets_.push_back(
       TransmissionInfo(frames,
-                       new_sequence_number,
                        transmission_info->sequence_number_length,
                        transmission_type,
                        transmission_info->all_transmissions));
@@ -114,7 +117,7 @@ void QuicUnackedPacketMap::ClearPreviousRetransmissions(size_t num_to_clear) {
       break;
     }
 
-    info->all_transmissions->erase(least_unacked_);
+    info->all_transmissions->pop_front();
     LOG_IF(DFATAL, info->all_transmissions->empty())
         << "Previous retransmissions must have a newer transmission.";
     unacked_packets_.pop_front();
@@ -145,20 +148,19 @@ void QuicUnackedPacketMap::RemoveRetransmittability(
   DCHECK_GE(sequence_number, least_unacked_);
   DCHECK_LT(sequence_number, least_unacked_ + unacked_packets_.size());
   TransmissionInfo* info = &unacked_packets_[sequence_number - least_unacked_];
-  SequenceNumberSet* all_transmissions = info->all_transmissions;
-  if (all_transmissions->size() == 1) {
+  SequenceNumberList* all_transmissions = info->all_transmissions;
+  if (all_transmissions == NULL) {
     MaybeRemoveRetransmittableFrames(info);
     return;
   }
   // TODO(ianswett): Consider adding a check to ensure there are retransmittable
   // frames associated with this packet.
-  for (SequenceNumberSet::const_iterator it = all_transmissions->begin();
+  for (SequenceNumberList::const_iterator it = all_transmissions->begin();
        it != all_transmissions->end(); ++it) {
     TransmissionInfo* transmission_info =
         &unacked_packets_[*it - least_unacked_];
     MaybeRemoveRetransmittableFrames(transmission_info);
-    transmission_info->all_transmissions = new SequenceNumberSet();
-    transmission_info->all_transmissions->insert(*it);
+    transmission_info->all_transmissions = NULL;
   }
   delete all_transmissions;
 }
@@ -187,7 +189,7 @@ bool QuicUnackedPacketMap::IsPacketUseless(
   return sequence_number <= largest_observed_ &&
       !info.in_flight &&
       info.retransmittable_frames == NULL &&
-      info.all_transmissions->size() == 1;
+      info.all_transmissions == NULL;
 }
 
 bool QuicUnackedPacketMap::IsUnacked(