Update QuicSentPacketManager to sample a new recent min rtt within the

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_config_peer.h"
 #include "net/quic/test_tools/quic_sent_packet_manager_peer.h"
 #include "net/quic/test_tools/quic_test_utils.h"
@@ skipping 1016 matching lines @@
   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, ResetRecentMinRTTWithEmptyWindow) {
+  QuicTime::Delta min_rtt = QuicTime::Delta::FromMilliseconds(50);
+  QuicSentPacketManagerPeer::GetRttStats(&manager_)->UpdateRtt(
+      min_rtt, QuicTime::Delta::Zero(), QuicTime::Zero());
+  EXPECT_EQ(min_rtt,
+            QuicSentPacketManagerPeer::GetRttStats(&manager_)->min_rtt());
+  EXPECT_EQ(min_rtt,
+            QuicSentPacketManagerPeer::GetRttStats(
+                &manager_)->recent_min_rtt());
+
+  // Send two packets with no prior bytes in flight.
+  SendDataPacket(1);
+  SendDataPacket(2);
+
+  clock_.AdvanceTime(QuicTime::Delta::FromMilliseconds(100));
+  // Ack two packets with 100ms RTT observations.
+  ReceivedPacketInfo received_info;
+  received_info.delta_time_largest_observed = QuicTime::Delta::Zero();
+  received_info.largest_observed = 1;
+  ExpectAck(1);
+  manager_.OnIncomingAck(received_info, clock_.Now());
+
+  // First ack does not change recent min rtt.
+  EXPECT_EQ(min_rtt,
+            QuicSentPacketManagerPeer::GetRttStats(
+                &manager_)->recent_min_rtt());
+
+  received_info.largest_observed = 2;
+  ExpectAck(2);
+  manager_.OnIncomingAck(received_info, clock_.Now());
+
+  EXPECT_EQ(min_rtt,
+            QuicSentPacketManagerPeer::GetRttStats(&manager_)->min_rtt());
+  EXPECT_EQ(QuicTime::Delta::FromMilliseconds(100),
+            QuicSentPacketManagerPeer::GetRttStats(
+                &manager_)->recent_min_rtt());
+}
+
 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 182 matching lines @@
 
   EXPECT_EQ(kTime,
             QuicSentPacketManagerPeer::GetLossAlgorithm(
                 &manager_)->GetLossDetectionType());
 }
 
 
 }  // namespace
 }  // namespace test
 }  // namespace net