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

net/quic/core/quic_packet_generator.h

Index: net/quic/core/quic_packet_generator.h
diff --git a/net/quic/core/quic_packet_generator.h b/net/quic/core/quic_packet_generator.h
index 43bffc1f4a4b8e786b12549ce2fc286fe8d65a2b..1b04881e681ff3be8117018703cc3058e05b3885 100644
--- a/net/quic/core/quic_packet_generator.h
+++ b/net/quic/core/quic_packet_generator.h
@@ -180,6 +180,9 @@ class QUIC_EXPORT_PRIVATE QuicPacketGenerator {
   // when there are frames queued in the creator.
   void SetMaxPacketLength(QuicByteCount length);
 
+  // Let delegate save stream data in creator.
+  void SetDelegateSavesData(bool delegate_saves_data);
+
   void set_debug_delegate(QuicPacketCreator::DebugDelegate* debug_delegate) {
     packet_creator_.set_debug_delegate(debug_delegate);
   }