diff --git a/quic/core/quic_stream_test.cc b/quic/core/quic_stream_test.cc
index 411d6d0..eaeb630 100644
--- a/quic/core/quic_stream_test.cc
+++ b/quic/core/quic_stream_test.cc
@@ -301,11 +301,7 @@
                                             NO_FIN);
       }));
   stream_->WriteOrBufferData(QuicStringPiece(kData1, 2), false, nullptr);
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   ASSERT_EQ(1u, write_blocked_list_->NumBlockedStreams());
   EXPECT_EQ(1u, stream_->BufferedDataBytes());
 }
@@ -323,11 +319,7 @@
                                             NO_FIN);
       }));
   stream_->WriteOrBufferData(QuicStringPiece(kData1, 2), true, nullptr);
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   ASSERT_EQ(1u, write_blocked_list_->NumBlockedStreams());
 }
 
@@ -374,11 +366,7 @@
       }));
   stream_->WriteOrBufferData(kData1, false, nullptr);
 
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(1u, stream_->BufferedDataBytes());
   EXPECT_TRUE(HasWriteBlockedStreams());
 
@@ -393,11 +381,7 @@
                                             kDataLen - 1, kDataLen - 1, NO_FIN);
       }));
   stream_->OnCanWrite();
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
 
   // And finally the end of the bytes_consumed.
   EXPECT_CALL(*session_, WritevData(_, _, _, _, _))
@@ -406,11 +390,7 @@
                                             2 * kDataLen - 2, NO_FIN);
       }));
   stream_->OnCanWrite();
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
 }
 
 TEST_P(QuicStreamTest, WriteOrBufferDataReachStreamLimit) {
@@ -421,11 +401,7 @@
   EXPECT_CALL(*session_, WritevData(_, _, _, _, _))
       .WillOnce(Invoke(&(MockQuicSession::ConsumeData)));
   stream_->WriteOrBufferData(data, false, nullptr);
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_CALL(*connection_, CloseConnection(QUIC_STREAM_LENGTH_OVERFLOW, _, _));
   EXPECT_QUIC_BUG(stream_->WriteOrBufferData("a", false, nullptr),
                   "Write too many data via stream");
@@ -460,11 +436,7 @@
                                             NO_FIN);
       }));
   stream_->WriteOrBufferData(QuicStringPiece(kData1, 1), false, nullptr);
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_FALSE(fin_sent());
   EXPECT_FALSE(rst_sent());
 
@@ -834,11 +806,7 @@
 
   // Send kData1.
   stream_->WriteOrBufferData(kData1, false, nullptr);
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(1u, QuicStreamPeer::SendBuffer(stream_).size());
   EXPECT_TRUE(stream_->IsWaitingForAcks());
   QuicByteCount newly_acked_length = 0;
@@ -853,11 +821,7 @@
   // Send kData2.
   stream_->WriteOrBufferData(kData2, false, nullptr);
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(1u, QuicStreamPeer::SendBuffer(stream_).size());
   // Send FIN.
   stream_->WriteOrBufferData("", true, nullptr);
@@ -873,11 +837,7 @@
   EXPECT_EQ(9u, newly_acked_length);
   // Stream is waiting for acks as FIN is not acked.
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(0u, QuicStreamPeer::SendBuffer(stream_).size());
 
   // FIN is acked.
@@ -900,46 +860,26 @@
   stream_->WriteOrBufferData("", true, nullptr);
   EXPECT_EQ(3u, QuicStreamPeer::SendBuffer(stream_).size());
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   QuicByteCount newly_acked_length = 0;
   EXPECT_TRUE(stream_->OnStreamFrameAcked(9, 9, false, QuicTime::Delta::Zero(),
                                           &newly_acked_length));
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(9u, newly_acked_length);
   EXPECT_EQ(3u, QuicStreamPeer::SendBuffer(stream_).size());
   EXPECT_TRUE(stream_->OnStreamFrameAcked(18, 9, false, QuicTime::Delta::Zero(),
                                           &newly_acked_length));
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(9u, newly_acked_length);
   EXPECT_EQ(3u, QuicStreamPeer::SendBuffer(stream_).size());
   EXPECT_TRUE(stream_->OnStreamFrameAcked(0, 9, false, QuicTime::Delta::Zero(),
                                           &newly_acked_length));
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(9u, newly_acked_length);
   EXPECT_EQ(0u, QuicStreamPeer::SendBuffer(stream_).size());
   // FIN is not acked yet.
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_TRUE(stream_->OnStreamFrameAcked(27, 0, true, QuicTime::Delta::Zero(),
                                           &newly_acked_length));
   EXPECT_EQ(0u, newly_acked_length);
@@ -957,22 +897,14 @@
 
   stream_->WriteOrBufferData(kData1, false, nullptr);
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(1u, QuicStreamPeer::SendBuffer(stream_).size());
   // Cancel stream.
   stream_->Reset(QUIC_STREAM_NO_ERROR);
   // stream still waits for acks as the error code is QUIC_STREAM_NO_ERROR, and
   // data is going to be retransmitted.
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_CALL(*connection_,
               OnStreamReset(stream_->id(), QUIC_STREAM_CANCELLED));
   EXPECT_CALL(*connection_, SendControlFrame(_)).Times(1);
@@ -1007,11 +939,7 @@
 
   stream_->WriteOrBufferData(kData1, false, nullptr);
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(1u, QuicStreamPeer::SendBuffer(stream_).size());
 
   // RST_STREAM received.
@@ -1037,11 +965,7 @@
 
   stream_->WriteOrBufferData(kData1, true, nullptr);
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
 
   // RST_STREAM received.
   EXPECT_CALL(*session_, SendRstStream(_, _, _)).Times(0);
@@ -1050,11 +974,7 @@
   stream_->OnStreamReset(rst_frame);
   // Stream still waits for acks as it finishes sending and has unacked data.
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_EQ(1u, QuicStreamPeer::SendBuffer(stream_).size());
 }
 
@@ -1068,11 +988,7 @@
 
   stream_->WriteOrBufferData(kData1, false, nullptr);
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   EXPECT_CALL(*session_,
               SendRstStream(stream_->id(), QUIC_RST_ACKNOWLEDGEMENT, 9));
   stream_->OnConnectionClosed(QUIC_INTERNAL_ERROR,
@@ -1328,11 +1244,7 @@
   stream_->WriteOrBufferData(kData1, true, nullptr);
   EXPECT_EQ(3u, QuicStreamPeer::SendBuffer(stream_).size());
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
   // Ack [0, 9), [5, 22) and [18, 26)
   // Verify [0, 9) 9 bytes are acked.
   QuicByteCount newly_acked_length = 0;
@@ -1351,11 +1263,7 @@
   EXPECT_EQ(4u, newly_acked_length);
   EXPECT_EQ(1u, QuicStreamPeer::SendBuffer(stream_).size());
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
 
   // Ack [0, 27). Verify [26, 27) 1 byte is acked.
   EXPECT_TRUE(stream_->OnStreamFrameAcked(26, 1, false, QuicTime::Delta::Zero(),
@@ -1363,11 +1271,7 @@
   EXPECT_EQ(1u, newly_acked_length);
   EXPECT_EQ(0u, QuicStreamPeer::SendBuffer(stream_).size());
   EXPECT_TRUE(stream_->IsWaitingForAcks());
-  // Session decides what to write and puts stream into set of unacked streams
-  // only after v39.
-  if (GetParam().transport_version > QUIC_VERSION_39) {
-    EXPECT_TRUE(session_->HasUnackedStreamData());
-  }
+  EXPECT_TRUE(session_->HasUnackedStreamData());
 
   // Ack Fin.
   EXPECT_TRUE(stream_->OnStreamFrameAcked(27, 0, true, QuicTime::Delta::Zero(),
@@ -1581,10 +1485,6 @@
 }
 
 TEST_P(QuicStreamTest, ResetStreamOnTtlExpiresRetransmitLostData) {
-  // Version 39 and below doesn't support stream ttl.
-  if (GetParam().transport_version <= QUIC_VERSION_39) {
-    return;
-  }
   Initialize();
 
   EXPECT_CALL(*session_, WritevData(_, stream_->id(), 200, 0, FIN))
@@ -1609,10 +1509,6 @@
 }
 
 TEST_P(QuicStreamTest, ResetStreamOnTtlExpiresEarlyRetransmitData) {
-  // Version 39 and below doesn't support stream ttl.
-  if (GetParam().transport_version <= QUIC_VERSION_39) {
-    return;
-  }
   Initialize();
 
   EXPECT_CALL(*session_, WritevData(_, stream_->id(), 200, 0, FIN))