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.cc b/quic/core/quic_connection.cc
index efc89d3..cb901ba 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -1261,15 +1261,6 @@
   return connected_;
 }
 
-bool QuicConnection::OnApplicationCloseFrame(
-    const QuicConnectionCloseFrame& frame) {
-  // TODO(fkastenholz): Need to figure out what the right thing is to do with
-  // this when we get one. Most likely, the correct action is to mimic the
-  // OnConnectionCloseFrame actions, with possibly an indication to the
-  // application of the ApplicationClose information.
-  return true;
-}
-
 bool QuicConnection::OnStopSendingFrame(const QuicStopSendingFrame& frame) {
   DCHECK(connected_);
 
@@ -3053,6 +3044,8 @@
   }
   QuicConnectionCloseFrame* frame =
       new QuicConnectionCloseFrame(error, details);
+  // If version99/IETF QUIC set the close type. Default close type is Google
+  // QUIC.
   if (transport_version() == QUIC_VERSION_99) {
     frame->close_type = IETF_QUIC_TRANSPORT_CONNECTION_CLOSE;
   }