Add class QuicMultipathReceivedPacketManager (not in use currently).

net/quic/quic_received_packet_manager.h

Index: net/quic/quic_received_packet_manager.h
diff --git a/net/quic/quic_received_packet_manager.h b/net/quic/quic_received_packet_manager.h
index fa48f50c9a225bcd8f5ff225fe84c45599160075..b5ee73dd5fa5b1b3d6c740f420cac84c5d5a2ad2 100644
--- a/net/quic/quic_received_packet_manager.h
+++ b/net/quic/quic_received_packet_manager.h
@@ -102,17 +102,17 @@ class NET_EXPORT_PRIVATE QuicReceivedPacketManager :
   // bytes: the packet size in bytes including Quic Headers.
   // header: the packet header.
   // timestamp: the arrival time of the packet.
-  void RecordPacketReceived(QuicByteCount bytes,
-                            const QuicPacketHeader& header,
-                            QuicTime receipt_time);
+  virtual void RecordPacketReceived(QuicByteCount bytes,
+                                    const QuicPacketHeader& header,
+                                    QuicTime receipt_time);
 
-  void RecordPacketRevived(QuicPacketNumber packet_number);
+  virtual void RecordPacketRevived(QuicPacketNumber packet_number);
 
   // Checks whether |packet_number| is missing and less than largest observed.
-  bool IsMissing(QuicPacketNumber packet_number);
+  virtual bool IsMissing(QuicPacketNumber packet_number);
 
   // Checks if we're still waiting for the packet with |packet_number|.
-  bool IsAwaitingPacket(QuicPacketNumber packet_number);
+  virtual bool IsAwaitingPacket(QuicPacketNumber packet_number);
 
   // Update the |ack_frame| for an outgoing ack.
   void UpdateReceivedPacketInfo(QuicAckFrame* ack_frame,
@@ -125,12 +125,12 @@ class NET_EXPORT_PRIVATE QuicReceivedPacketManager :
       QuicPacketNumber packet_number) const override;
 
   // Updates internal state based on |stop_waiting|.
-  void UpdatePacketInformationSentByPeer(
+  virtual void UpdatePacketInformationSentByPeer(
       const QuicStopWaitingFrame& stop_waiting);
 
   // Returns true when there are new missing packets to be reported within 3
   // packets of the largest observed.
-  bool HasNewMissingPackets() const;
+  virtual bool HasNewMissingPackets() const;
 
   // Returns the number of packets being tracked in the EntropyTracker.
   size_t NumTrackedPackets() const;
@@ -139,7 +139,7 @@ class NET_EXPORT_PRIVATE QuicReceivedPacketManager :
     return peer_least_packet_awaiting_ack_;
   }
 
-  bool ack_frame_updated() const { return ack_frame_updated_; }
+  virtual bool ack_frame_updated() const;
 
  private:
   friend class test::QuicConnectionPeer;