Remove a QUIC test only flag(limit_rto_increase_for_tests) to limit the

net/quic/quic_sent_packet_manager.cc

Index: net/quic/quic_sent_packet_manager.cc
diff --git a/net/quic/quic_sent_packet_manager.cc b/net/quic/quic_sent_packet_manager.cc
index 9282038e980aff84d671a514ca13e8739c2d2640..81da4798b2889fb7bbfc8b96e5a38b0f590fd22a 100644
--- a/net/quic/quic_sent_packet_manager.cc
+++ b/net/quic/quic_sent_packet_manager.cc
@@ -21,10 +21,6 @@ using std::min;
 // other transmissions.
 bool FLAGS_track_retransmission_history = false;
 
-// A test-only flag to prevent the RTO from backing off when multiple sequential
-// tail drops occur.
-bool FLAGS_limit_rto_increase_for_tests = false;
-
 // Do not remove this flag until the Finch-trials described in b/11706275
 // are complete.
 // If true, QUIC connections will support the use of a pacing algorithm when
@@ -857,8 +853,8 @@ const QuicTime QuicSentPacketManager::GetRetransmissionTime() const {
   return QuicTime::Zero();
 }
 
-const QuicTime::Delta
-QuicSentPacketManager::GetCryptoRetransmissionDelay() const {
+const QuicTime::Delta QuicSentPacketManager::GetCryptoRetransmissionDelay()
+    const {
   // This is equivalent to the TailLossProbeDelay, but slightly more aggressive
   // because crypto handshake messages don't incur a delayed ack time.
   int64 delay_ms = max<int64>(kMinHandshakeTimeoutMs,
@@ -879,24 +875,6 @@ const QuicTime::Delta QuicSentPacketManager::GetTailLossProbeDelay() const {
 }
 
 const QuicTime::Delta QuicSentPacketManager::GetRetransmissionDelay() const {
-  size_t number_retransmissions = consecutive_rto_count_;
-  // TODO(ianswett): Remove this flag now that EndToEndTest is no longer flaky.
-  if (FLAGS_limit_rto_increase_for_tests) {
-    const size_t kTailDropWindowSize = 5;
-    const size_t kTailDropMaxRetransmissions = 4;
-    if (pending_packets_.size() <= kTailDropWindowSize) {
-      // Avoid exponential backoff of RTO when there are only a few packets
-      // outstanding.  This helps avoid the situation where fake packet loss
-      // causes a packet and it's retransmission to be dropped causing
-      // test timouts.
-      if (number_retransmissions <= kTailDropMaxRetransmissions) {
-        number_retransmissions = 0;
-      } else {
-        number_retransmissions -= kTailDropMaxRetransmissions;
-      }
-    }
-  }
-
   QuicTime::Delta retransmission_delay = send_algorithm_->RetransmissionDelay();
   if (retransmission_delay.IsZero()) {
     // We are in the initial state, use default timeout values.
@@ -905,7 +883,7 @@ const QuicTime::Delta QuicSentPacketManager::GetRetransmissionDelay() const {
   }
   // Calculate exponential back off.
   retransmission_delay = retransmission_delay.Multiply(
-      1 << min<size_t>(number_retransmissions, kMaxRetransmissions));
+      1 << min<size_t>(consecutive_rto_count_, kMaxRetransmissions));
 
   // TODO(rch): This code should move to |send_algorithm_|.
   if (retransmission_delay.ToMilliseconds() < kMinRetransmissionTimeMs) {