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

Index: net/quic/test_tools/quic_stream_peer.h
diff --git a/net/quic/test_tools/quic_stream_peer.h b/net/quic/test_tools/quic_stream_peer.h
index b7c33565303edd520a0cb204402b02069fdcb1f2..3f1ce4439530f7f5e18164112a534da9a5332b9e 100644
--- a/net/quic/test_tools/quic_stream_peer.h
+++ b/net/quic/test_tools/quic_stream_peer.h
@@ -9,6 +9,7 @@
 
 #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"
 
@@ -43,6 +44,8 @@ class QuicStreamPeer {
   static QuicStreamSequencer* sequencer(QuicStream* stream);
   static QuicSession* session(QuicStream* stream);
 
+  static QuicStreamSendBuffer& SendBuffer(QuicStream* stream);
+
  private:
   DISALLOW_COPY_AND_ASSIGN(QuicStreamPeer);
 };