In QUIC, send data is copied to streams rather than frames. Protected by FLAGS_quic_reloadable_flag…

net/quic/test_tools/quic_stream_peer.h

 // 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.
 
 #ifndef NET_QUIC_TEST_TOOLS_QUIC_STREAM_PEER_H_
 #define NET_QUIC_TEST_TOOLS_QUIC_STREAM_PEER_H_
 
 #include <cstdint>
 
 #include "base/macros.h"
 #include "net/quic/core/quic_packets.h"
+#include "net/quic/core/quic_stream_send_buffer.h"
 #include "net/quic/core/quic_stream_sequencer.h"
 #include "net/quic/platform/api/quic_string_piece.h"
 
 namespace net {
 
 class QuicStream;
 class QuicSession;
 
 namespace test {
 
@@ skipping 14 matching lines @@
 
   static void WriteOrBufferData(
       QuicStream* stream,
       QuicStringPiece data,
       bool fin,
       QuicReferenceCountedPointer<QuicAckListenerInterface> ack_listener);
 
   static QuicStreamSequencer* sequencer(QuicStream* stream);
   static QuicSession* session(QuicStream* stream);
 
+  static QuicStreamSendBuffer& SendBuffer(QuicStream* stream);
+
  private:
   DISALLOW_COPY_AND_ASSIGN(QuicStreamPeer);
 };
 
 }  // namespace test
 
 }  // namespace net
 
 #endif  // NET_QUIC_TEST_TOOLS_QUIC_STREAM_PEER_H_