Add logging only ack_frame accessor.

gfe-relnote: n/a (logging only change)
PiperOrigin-RevId: 248533601
Change-Id: I1a72e6caed4c322ede61f4378f42ffbc161d55a7
diff --git a/quic/core/quic_connection.h b/quic/core/quic_connection.h
index 413a582..8c8ed2b 100644
--- a/quic/core/quic_connection.h
+++ b/quic/core/quic_connection.h
@@ -526,6 +526,8 @@
   bool ShouldGeneratePacket(HasRetransmittableData retransmittable,
                             IsHandshake handshake) override;
   const QuicFrames MaybeBundleAckOpportunistically() override;
+  // Please note, this is not a const function. For logging purpose, please use
+  // ack_frame().
   const QuicFrame GetUpdatedAckFrame() override;
   void PopulateStopWaitingFrame(QuicStopWaitingFrame* stop_waiting) override;
 
@@ -887,6 +889,9 @@
   // Returns true if this connection supports multiple packet number spaces.
   bool SupportsMultiplePacketNumberSpaces() const;
 
+  // For logging purpose.
+  const QuicAckFrame& ack_frame() const;
+
  protected:
   // Calls cancel() on all the alarms owned by this connection.
   void CancelAllAlarms();