Remove RevertRetransmissionTimeout from QUIC's SendAlgorithmInterface

net/quic/congestion_control/tcp_cubic_sender_test.cc

 // Copyright (c) 2012 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 <algorithm>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "net/quic/congestion_control/rtt_stats.h"
 #include "net/quic/congestion_control/tcp_cubic_sender.h"
@@ skipping 232 matching lines @@
   EXPECT_EQ(expected_ss_tresh, sender_->GetSlowStartThreshold());
   EXPECT_EQ(140u, sender_->slowstart_threshold());
 
   // Now RTO and ensure slow start gets reset.
   EXPECT_TRUE(sender_->hybrid_slow_start().started());
   sender_->OnRetransmissionTimeout(true);
   EXPECT_FALSE(sender_->hybrid_slow_start().started());
   EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow());
   EXPECT_EQ(expected_send_window / 2 / kDefaultTCPMSS,
             sender_->slowstart_threshold());
-
-  // Now revert the RTO and ensure the CWND and slowstart threshold revert.
-  sender_->RevertRetransmissionTimeout();
-  EXPECT_EQ(expected_send_window, sender_->GetCongestionWindow());
-  EXPECT_EQ(140u, sender_->slowstart_threshold());
 }
 
 TEST_F(TcpCubicSenderTest, SlowStartPacketLoss) {
   sender_->SetNumEmulatedConnections(1);
   const int kNumberOfAcks = 10;
   for (int i = 0; i < kNumberOfAcks; ++i) {
     // Send our full send window.
     SendAvailableSendWindow();
     AckNPackets(2);
   }
@@ skipping 146 matching lines @@
   // Send 2 packets to simulate PRR-SSRB.
   EXPECT_EQ(2, SendAvailableSendWindow());
 
   // Exit recovery and return to sending at the new rate.
   for (int i = 0; i < kNumberOfAcks; ++i) {
     AckNPackets(1);
     EXPECT_EQ(1, SendAvailableSendWindow());
   }
 }
 
-TEST_F(TcpCubicSenderTest, RTOCongestionWindowAndRevert) {
+TEST_F(TcpCubicSenderTest, RTOCongestionWindow) {
   EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow());
   EXPECT_EQ(kMaxTcpCongestionWindow, sender_->slowstart_threshold());
 
   // Expect the window to decrease to the minimum once the RTO fires
   // and slow start threshold to be set to 1/2 of the CWND.
   sender_->OnRetransmissionTimeout(true);
   EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow());
   EXPECT_EQ(5u, sender_->slowstart_threshold());
-
-  // Now repair the RTO and ensure the slowstart threshold reverts.
-  sender_->RevertRetransmissionTimeout();
-  EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow());
-  EXPECT_EQ(kMaxTcpCongestionWindow, sender_->slowstart_threshold());
 }
 
 TEST_F(TcpCubicSenderTest, RTOCongestionWindowNoRetransmission) {
   EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow());
 
   // Expect the window to remain unchanged if the RTO fires but no
   // packets are retransmitted.
   sender_->OnRetransmissionTimeout(false);
   EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow());
 }
 
-TEST_F(TcpCubicSenderTest, RTOTwiceOnlyHalvesSsthresh) {
-  EXPECT_EQ(kDefaultWindowTCP, sender_->GetCongestionWindow());
-
-  sender_->OnRetransmissionTimeout(true);
-  EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow());
-  EXPECT_EQ(5u, sender_->slowstart_threshold());
-
-  sender_->OnRetransmissionTimeout(true);
-  EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow());
-  EXPECT_EQ(5u, sender_->slowstart_threshold());
-
-  AckNPackets(2);
-
-  EXPECT_EQ(4 * kDefaultTCPMSS, sender_->GetCongestionWindow());
-  EXPECT_EQ(5u, sender_->slowstart_threshold());
-
-  sender_->OnRetransmissionTimeout(true);
-  EXPECT_EQ(2 * kDefaultTCPMSS, sender_->GetCongestionWindow());
-  EXPECT_EQ(2u, sender_->slowstart_threshold());
-}
-
 TEST_F(TcpCubicSenderTest, RetransmissionDelay) {
   const int64 kRttMs = 10;
   const int64 kDeviationMs = 3;
   EXPECT_EQ(QuicTime::Delta::Zero(), sender_->RetransmissionDelay());
 
   sender_->rtt_stats_.UpdateRtt(QuicTime::Delta::FromMilliseconds(kRttMs),
                                 QuicTime::Delta::Zero(), clock_.Now());
 
   // Initial value is to set the median deviation to half of the initial
   // rtt, the median in then multiplied by a factor of 4 and finally the
@@ skipping 272 matching lines @@
 
   cached_network_params.set_bandwidth_estimate_bytes_per_second(
       (kMinCongestionWindowForBandwidthResumption - 1) * kMaxPacketSize);
   EXPECT_TRUE(sender_->ResumeConnectionState(cached_network_params));
   EXPECT_EQ(kMinCongestionWindowForBandwidthResumption,
             sender_->congestion_window());
 }
 
 }  // namespace test
 }  // namespace net