Replace QuicAckListenerInterface* with scoped_refptr<QuicAckListenerInterface>.

net/quic/core/quic_spdy_session.cc

Index: net/quic/core/quic_spdy_session.cc
diff --git a/net/quic/core/quic_spdy_session.cc b/net/quic/core/quic_spdy_session.cc
index d081b65a5030301f3ec6e37d3949e81227d60d6d..0fe39fa590e5e1a3e83ceaef5f178a04d5b08d30 100644
--- a/net/quic/core/quic_spdy_session.cc
+++ b/net/quic/core/quic_spdy_session.cc
@@ -74,7 +74,7 @@ size_t QuicSpdySession::WriteHeaders(
     SpdyHeaderBlock headers,
     bool fin,
     SpdyPriority priority,
-    QuicAckListenerInterface* ack_notifier_delegate) {
+    const scoped_refptr<QuicAckListenerInterface>& ack_notifier_delegate) {
   return headers_stream_->WriteHeaders(id, std::move(headers), fin, priority,
                                        ack_notifier_delegate);
 }