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

net/quic/core/quic_packet_generator.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.
 //
 // Responsible for generating packets on behalf of a QuicConnection.
 // Packets are serialized just-in-time.  Control frames are queued.
 // Ack and Feedback frames will be requested from the Connection
 // just-in-time.  When a packet needs to be sent, the Generator
 // will serialize a packet and pass it to QuicConnection::SendOrQueuePacket()
 //
@@ skipping 162 matching lines @@
   // created.
   QuicPacketNumber packet_number() const;
 
   // Returns the maximum length a current packet can actually have.
   QuicByteCount GetCurrentMaxPacketLength() const;
 
   // Set maximum packet length in the creator immediately.  May not be called
   // 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);
   }
 
   bool latched_flag_no_stop_waiting_frames() const {
     return packet_creator_.latched_flag_no_stop_waiting_frames();
   }
 
  private:
   friend class test::QuicPacketGeneratorPeer;
@@ skipping 36 matching lines @@
   QuicStopWaitingFrame pending_stop_waiting_frame_;
 
   QuicRandom* random_generator_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicPacketGenerator);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CORE_QUIC_PACKET_GENERATOR_H_