Land Recent QUIC Changes.

net/quic/quic_received_packet_manager.cc

Index: net/quic/quic_received_packet_manager.cc
diff --git a/net/quic/quic_received_packet_manager.cc b/net/quic/quic_received_packet_manager.cc
index 844ad43e37b14d3e746f957ec2b1d77c9d100998..b24ac7c671eaee7a728a3d46124bd84d9246ba9c 100644
--- a/net/quic/quic_received_packet_manager.cc
+++ b/net/quic/quic_received_packet_manager.cc
@@ -5,6 +5,7 @@
 #include "net/quic/quic_received_packet_manager.h"
 
 #include "base/logging.h"
+#include "base/stl_util.h"
 #include "net/base/linked_hash_map.h"
 
 using std::make_pair;
@@ -13,6 +14,17 @@ using std::min;
 
 namespace net {
 
+namespace {
+
+// The maximum number of packets to ack immediately after a missing packet for
+// fast retransmission to kick in at the sender.  This limit is created to
+// reduce the number of acks sent that have no benefit for fast retransmission.
+// Set to the number of nacks needed for fast retransmit plus one for protection
+// against an ack loss
+const size_t kMaxPacketsAfterNewMissing = 4;
+
+}
+
 QuicReceivedPacketManager::QuicReceivedPacketManager(
     CongestionFeedbackType congestion_type)
     : packets_entropy_hash_(0),
@@ -60,6 +72,11 @@ void QuicReceivedPacketManager::RecordPacketReceived(
   }
 }
 
+bool QuicReceivedPacketManager::IsMissing(
+    QuicPacketSequenceNumber sequence_number) {
+  return ContainsKey(received_info_.missing_packets, sequence_number);
+}
+
 bool QuicReceivedPacketManager::IsAwaitingPacket(
     QuicPacketSequenceNumber sequence_number) {
   return ::net::IsAwaitingPacket(received_info_, sequence_number);
@@ -213,4 +230,10 @@ bool QuicReceivedPacketManager::HasMissingPackets() {
   return !received_info_.missing_packets.empty();
 }
 
+bool QuicReceivedPacketManager::HasNewMissingPackets() {
+  return HasMissingPackets() &&
+      (received_info_.largest_observed -
+       *received_info_.missing_packets.rbegin()) <= kMaxPacketsAfterNewMissing;
+}
+
 }  // namespace net