Pass value and use std::move instead of const reference for ack listeners.

net/quic/core/quic_packet_generator.h

Index: net/quic/core/quic_packet_generator.h
diff --git a/net/quic/core/quic_packet_generator.h b/net/quic/core/quic_packet_generator.h
index be0215a776a3a33951986bbbd100d9f5cda9087b..ff5c319423b7d75328fb896ee5346a10f1424524 100644
--- a/net/quic/core/quic_packet_generator.h
+++ b/net/quic/core/quic_packet_generator.h
@@ -98,7 +98,7 @@ class QUIC_EXPORT_PRIVATE QuicPacketGenerator {
       QuicIOVector iov,
       QuicStreamOffset offset,
       bool fin,
-      const scoped_refptr<QuicAckListenerInterface>& listener);
+      scoped_refptr<QuicAckListenerInterface> listener);
 
   // Sends as many data only packets as allowed by the send algorithm and the
   // available iov.
@@ -108,12 +108,12 @@ class QUIC_EXPORT_PRIVATE QuicPacketGenerator {
       const QuicIOVector& iov,
       QuicStreamOffset offset,
       bool fin,
-      const scoped_refptr<QuicAckListenerInterface>& listener);
+      scoped_refptr<QuicAckListenerInterface> listener);
 
   // Generates an MTU discovery packet of specified size.
   void GenerateMtuDiscoveryPacket(
       QuicByteCount target_mtu,
-      const scoped_refptr<QuicAckListenerInterface>& listener);
+      scoped_refptr<QuicAckListenerInterface> listener);
 
   // Indicates whether batch mode is currently enabled.
   bool InBatchMode();