Implement the variable length changes necessary to easily accommodate

net/quic/test_tools/quic_test_utils.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 "net/quic/test_tools/quic_test_utils.h"
 
 #include "base/stl_util.h"
 #include "net/quic/crypto/crypto_framer.h"
 #include "net/quic/crypto/crypto_handshake.h"
 #include "net/quic/crypto/crypto_utils.h"
@@ skipping 364 matching lines @@
   return quic_framer.ConstructFrameDataPacket(header, frames).packet;
 }
 
 QuicPacket* ConstructHandshakePacket(QuicGuid guid, QuicTag tag) {
   CryptoHandshakeMessage message;
   message.set_tag(tag);
   return ConstructPacketFromHandshakeMessage(guid, message, false);
 }
 
 size_t GetPacketLengthForOneStream(
-    bool include_version, InFecGroup is_in_fec_group, size_t payload) {
-  // TODO(wtc): the hardcoded use of NullEncrypter here seems wrong.
-  size_t packet_length = NullEncrypter().GetCiphertextSize(payload) +
+    bool include_version, InFecGroup is_in_fec_group, size_t* payload_length) {
+  *payload_length = 1;
+  const size_t stream_length =
+      NullEncrypter().GetCiphertextSize(*payload_length) +
       QuicPacketCreator::StreamFramePacketOverhead(
-          1, PACKET_8BYTE_GUID, include_version,
+          PACKET_8BYTE_GUID, include_version,
           PACKET_6BYTE_SEQUENCE_NUMBER, is_in_fec_group);
-
-  size_t ack_length = NullEncrypter().GetCiphertextSize(
+  const size_t ack_length = NullEncrypter().GetCiphertextSize(
       QuicFramer::GetMinAckFrameSize()) +
       GetPacketHeaderSize(PACKET_8BYTE_GUID, include_version,
                           PACKET_6BYTE_SEQUENCE_NUMBER, is_in_fec_group);
-  // Make sure that if we change the size of the packet length for one stream
-  // or the ack frame; that all our test are configured correctly.
-  DCHECK_GE(packet_length, ack_length);
-  return packet_length;
+  if (stream_length < ack_length) {
+    *payload_length = 1 + ack_length - stream_length;
+  }
+
+  return NullEncrypter().GetCiphertextSize(*payload_length) +
+      QuicPacketCreator::StreamFramePacketOverhead(
+          PACKET_8BYTE_GUID, include_version,
+          PACKET_6BYTE_SEQUENCE_NUMBER, is_in_fec_group);
 }
 
 QuicPacketEntropyHash TestEntropyCalculator::ReceivedEntropyHash(
     QuicPacketSequenceNumber sequence_number) const {
   return 1u;
 }
 
 QuicConfig DefaultQuicConfig() {
   QuicConfig config;
   config.SetDefaults();
   return config;
 }
 
 bool TestDecompressorVisitor::OnDecompressedData(StringPiece data) {
   data.AppendToString(&data_);
   return true;
 }
 
 void TestDecompressorVisitor::OnDecompressionError() {
   error_ = true;
 }
 
 }  // namespace test
 }  // namespace net