Replace the map in QuicAckNotifier with a counter.

net/quic/quic_ack_notifier_manager.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/quic_ack_notifier_manager.h"
 
 #include <stddef.h>
 #include <list>
 #include <map>
 #include <utility>
@@ skipping 32 matching lines @@
       delete ack_notifier;
       ack_notifiers_.erase(ack_notifier);
     }
   }
 
   // Remove the sequence number from the map as we have notified all the
   // registered AckNotifiers, and we won't see it again.
   ack_notifier_map_.erase(map_it);
 }
 
-void AckNotifierManager::UpdateSequenceNumber(
+void AckNotifierManager::OnPacketRetransmitted(
     QuicPacketSequenceNumber old_sequence_number,
-    QuicPacketSequenceNumber new_sequence_number) {
+    QuicPacketSequenceNumber new_sequence_number,
+    int packet_payload_size) {
   auto map_it = ack_notifier_map_.find(old_sequence_number);
   if (map_it == ack_notifier_map_.end()) {
     // No AckNotifiers are interested in the old sequence number.
     return;
   }
 
   // Update the existing QuicAckNotifiers to the new sequence number.
   AckNotifierList& ack_notifier_list = map_it->second;
   for (QuicAckNotifier* ack_notifier : ack_notifier_list) {
-    ack_notifier->UpdateSequenceNumber(old_sequence_number,
-                                       new_sequence_number);
+    ack_notifier->OnPacketRetransmitted(packet_payload_size);
   }
 
   // The old sequence number is no longer of interest, copy the updated
   // AckNotifiers to the new sequence number before deleting the old.
   ack_notifier_map_[new_sequence_number] = ack_notifier_list;
   ack_notifier_map_.erase(map_it);
 }
 
 void AckNotifierManager::OnSerializedPacket(
     const SerializedPacket& serialized_packet) {
@@ skipping 37 matching lines @@
       // AckNotifier.
       ack_notifier_map_[serialized_packet.sequence_number].push_back(notifier);
 
       // Take ownership of the AckNotifier.
       ack_notifiers_.insert(notifier);
     }
   }
 }
 
 }  // namespace net