Deprecate FLAGS_quic_do_not_send_ack_on_emsgsize.

net/quic/core/quic_connection.cc

Index: net/quic/core/quic_connection.cc
diff --git a/net/quic/core/quic_connection.cc b/net/quic/core/quic_connection.cc
index f8d0049da3523e1c85741909abb710e34b7b714a..5793b15c890fc76a99d8563d77a2a59664f47fe1 100644
--- a/net/quic/core/quic_connection.cc
+++ b/net/quic/core/quic_connection.cc
@@ -1786,10 +1786,7 @@ void QuicConnection::OnWriteError(int error_code) {
       if (FLAGS_quic_close_connection_on_packet_too_large) {  // NOLINT
         CloseConnection(
             QUIC_PACKET_WRITE_ERROR, error_details,
-            FLAGS_quic_do_not_send_ack_on_emsgsize
-                ? ConnectionCloseBehavior::
-                      SEND_CONNECTION_CLOSE_PACKET_WITH_NO_ACK
-                : ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET);
+            ConnectionCloseBehavior::SEND_CONNECTION_CLOSE_PACKET_WITH_NO_ACK);
         break;
       }
     default: