Remove OnApplicationClose upcalls, update OnConnectionClose as needed.

Replaces the OnApplicationClose visitor upcalls with OnConnectionClose. The IETF removes the separate Application Close frame from QUIC, modifying the Connection Close frame to have two flavors; one for Application-initiated reasons, the other for Transport reasons. These were formerly the Application- and Connection- closes.

gfe-relnote: N/A this is only for IETF QUIC (version 99).
PiperOrigin-RevId: 243856589
Change-Id: Ie048aa2a8641f7e3f84b6cd7e4fc6ce61d5683e7
diff --git a/quic/core/quic_connection.h b/quic/core/quic_connection.h
index d13458d..c921d1b 100644
--- a/quic/core/quic_connection.h
+++ b/quic/core/quic_connection.h
@@ -250,13 +250,11 @@
   // Called when a RstStreamFrame has been parsed.
   virtual void OnRstStreamFrame(const QuicRstStreamFrame& frame) {}
 
-  // Called when a ConnectionCloseFrame has been parsed.
+  // Called when a ConnectionCloseFrame has been parsed. All forms
+  // of CONNECTION CLOSE are handled, Google QUIC, IETF QUIC
+  // CONNECTION CLOSE/Transport and IETF QUIC CONNECTION CLOSE/Application
   virtual void OnConnectionCloseFrame(const QuicConnectionCloseFrame& frame) {}
 
-  // Called when an IETF QUIC CONNECTION_CLOSE/Application Frame has been
-  // parsed.
-  virtual void OnApplicationCloseFrame(const QuicConnectionCloseFrame& frame) {}
-
   // Called when a WindowUpdate has been parsed.
   virtual void OnWindowUpdateFrame(const QuicWindowUpdateFrame& frame,
                                    const QuicTime& receive_time) {}
@@ -498,7 +496,6 @@
   bool OnPingFrame(const QuicPingFrame& frame) override;
   bool OnRstStreamFrame(const QuicRstStreamFrame& frame) override;
   bool OnConnectionCloseFrame(const QuicConnectionCloseFrame& frame) override;
-  bool OnApplicationCloseFrame(const QuicConnectionCloseFrame& frame) override;
   bool OnStopSendingFrame(const QuicStopSendingFrame& frame) override;
   bool OnPathChallengeFrame(const QuicPathChallengeFrame& frame) override;
   bool OnPathResponseFrame(const QuicPathResponseFrame& frame) override;