Handle PINGs in QUIC connection.

Currently, sending and retransmission of PINGs are handled by control frame manager (and session).

Protected by FLAGS_quic_reloadable_flag_quic_let_connection_handle_pings.

PiperOrigin-RevId: 335072367
Change-Id: I79f20404656beee3d9404c1ccaa8ef2f00af567c
diff --git a/quic/core/quic_packet_creator.h b/quic/core/quic_packet_creator.h
index b025d06..b65bd27 100644
--- a/quic/core/quic_packet_creator.h
+++ b/quic/core/quic_packet_creator.h
@@ -469,6 +469,10 @@
   // different from the current one, flush all the queue frames first.
   void SetDefaultPeerAddress(QuicSocketAddress address);
 
+  bool let_connection_handle_pings() const {
+    return let_connection_handle_pings_;
+  }
+
  private:
   friend class test::QuicPacketCreatorPeer;
 
@@ -665,6 +669,9 @@
 
   const bool close_connection_on_serialization_failure_ =
       GetQuicReloadableFlag(quic_close_connection_on_serialization_failure);
+
+  const bool let_connection_handle_pings_ =
+      GetQuicReloadableFlag(quic_let_connection_handle_pings);
 };
 
 }  // namespace quic