Add a test requested by rch@ in cr/59053386 to replicate a potential

net/quic/quic_sent_packet_manager_test.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_sent_packet_manager.h"
 
 #include "base/stl_util.h"
 #include "net/quic/test_tools/quic_sent_packet_manager_peer.h"
 #include "net/quic/test_tools/quic_test_utils.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ skipping 1020 matching lines @@
 
   // Retransmit 2 crypto packets, but not the serialized packet.
   EXPECT_CALL(*send_algorithm_, OnPacketAbandoned(_, _)).Times(2);
   manager_.OnRetransmissionTimeout();
   RetransmitNextPacket(6);
   RetransmitNextPacket(7);
   EXPECT_FALSE(manager_.HasPendingRetransmissions());
   EXPECT_TRUE(QuicSentPacketManagerPeer::HasUnackedCryptoPackets(&manager_));
 }
 
+TEST_F(QuicSentPacketManagerTest, TailLossProbeTimeoutUnsentDataPacket) {
+  QuicSentPacketManagerPeer::SetMaxTailLossProbes(&manager_, 2);
+  // Serialize two data packets and send the latter.
+  SerializedPacket packet(CreateDataPacket(1));
+  manager_.OnSerializedPacket(packet);
+  SendDataPacket(2);
+  EXPECT_FALSE(QuicSentPacketManagerPeer::HasUnackedCryptoPackets(&manager_));
+  EXPECT_TRUE(QuicSentPacketManagerPeer::HasPendingPackets(&manager_));
+
+  // Retransmit 1 unacked packets, but not the first serialized packet.
+  manager_.OnRetransmissionTimeout();
+  RetransmitNextPacket(3);
+  EXPECT_FALSE(manager_.HasPendingRetransmissions());
+  EXPECT_FALSE(QuicSentPacketManagerPeer::HasUnackedCryptoPackets(&manager_));
+  EXPECT_TRUE(QuicSentPacketManagerPeer::HasPendingPackets(&manager_));
+}
+
 TEST_F(QuicSentPacketManagerTest, RetransmissionTimeout) {
   // Send 100 packets and then ensure all are abandoned when the RTO fires.
   const size_t kNumSentPackets = 100;
   for (size_t i = 1; i <= kNumSentPackets; ++i) {
     SendDataPacket(i);
   }
 
   EXPECT_CALL(*send_algorithm_, OnRetransmissionTimeout(true));
   manager_.OnRetransmissionTimeout();
 }
@@ skipping 118 matching lines @@
     delay = delay.Add(delay);
     EXPECT_CALL(*send_algorithm_, OnRetransmissionTimeout(true));
     manager_.OnRetransmissionTimeout();
     RetransmitNextPacket(i + 2);
   }
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net