Make QuicDispatcher's helper argument be a unique_ptr to make ownership

net/tools/quic/quic_dispatcher.h

Index: net/tools/quic/quic_dispatcher.h
diff --git a/net/tools/quic/quic_dispatcher.h b/net/tools/quic/quic_dispatcher.h
index 5674a29dbed32e84b8a871a18036afe04dbfeaa8..44e1f5c3d116c8d1eceef70cbcd750e4afa5cc06 100644
--- a/net/tools/quic/quic_dispatcher.h
+++ b/net/tools/quic/quic_dispatcher.h
@@ -44,14 +44,10 @@ class QuicDispatcher : public QuicServerSessionVisitor,
                           QuicBlockedWriterInterfacePtrHash>
       WriteBlockedList;
 
-  // Due to the way delete_sessions_closure_ is registered, the Dispatcher must
-  // live until server Shutdown. |supported_versions| specifies the std::list
-  // of supported QUIC versions. Takes ownership of |packet_writer_factory|,
-  // which is used to create per-connection writers.
   QuicDispatcher(const QuicConfig& config,
                  const QuicCryptoServerConfig* crypto_config,
                  const QuicVersionVector& supported_versions,
-                 QuicConnectionHelperInterface* helper);
+                 std::unique_ptr<QuicConnectionHelperInterface> helper);
 
   ~QuicDispatcher() override;