Part of QUIC v39 change: 1) do not ack acks. 2) Send a WINDOW_UPDATE frame every 20 packets which d…

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 144 matching lines @@
   // can be safely changed.
   void UpdateSequenceNumberLength(QuicPacketNumber least_packet_awaited_by_peer,
                                   QuicPacketCount max_packets_in_flight);
 
   // Set the minimum number of bytes for the connection id length;
   void SetConnectionIdLength(uint32_t length);
 
   // Sets the encrypter to use for the encryption level.
   void SetEncrypter(EncryptionLevel level, QuicEncrypter* encrypter);
 
+  // Returns true if there are control frames or current constructed packet has
+  // pending retransmittable frames.
+  bool HasRetransmittableFrames() const;
+
   // Sets the encryption level that will be applied to new packets.
   void set_encryption_level(EncryptionLevel level);
 
   // packet number of the last created packet, or 0 if no packets have been
   // created.
   QuicPacketNumber packet_number() const;
 
   // Returns the maximum length a current packet can actually have.
   QuicByteCount GetCurrentMaxPacketLength() const;
 
@@ skipping 50 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_