Land Recent QUIC changes.

net/quic/quic_packet_creator.h

Index: net/quic/quic_packet_creator.h
diff --git a/net/quic/quic_packet_creator.h b/net/quic/quic_packet_creator.h
index 0e0a8c778938fc2c7a109947bb1d9020d8627046..68b62166fee70e1c116b84a678d38b2a228a951a 100644
--- a/net/quic/quic_packet_creator.h
+++ b/net/quic/quic_packet_creator.h
@@ -70,6 +70,12 @@ class NET_EXPORT_PRIVATE QuicPacketCreator : public QuicFecBuilderInterface {
   // Makes the framer not serialize the protocol version in sent packets.
   void StopSendingVersion();
 
+  // Update the sequence number length to use in future packets as soon as it
+  // can be safely changed.
+  void UpdateSequenceNumberLength(
+      QuicPacketSequenceNumber least_packet_awaited_by_peer,
+      QuicByteCount bytes_per_second);
+
   // The overhead the framing will add for a packet with one frame.
   static size_t StreamFramePacketOverhead(
       QuicVersion version,
@@ -152,6 +158,8 @@ class NET_EXPORT_PRIVATE QuicPacketCreator : public QuicFecBuilderInterface {
   QuicEncryptedPacket* SerializeVersionNegotiationPacket(
       const QuicVersionVector& supported_versions);
 
+  // Sequence number of the last created packet, or 0 if no packets have been
+  // created.
   QuicPacketSequenceNumber sequence_number() const {
     return sequence_number_;
   }