Listen: move ClientListener pointer to struct Partition

src/Partition.hxx

@@ -32,10 +32,12 @@
 #include "Compiler.h"
 
 #include <string>
+#include <memory>
 
 struct Instance;
 class MultipleOutputs;
 class SongLoader;
+class ClientListener;
 
 /**
  * A partition of the Music Player Daemon.  It is a separate unit with
@@ -49,6 +51,8 @@ struct Partition final : QueueListener, PlayerListener, MixerListener {
 
 	const std::string name;
 
+	std::unique_ptr<ClientListener> listener;
+
 	MaskMonitor global_events;
 
 	struct playlist playlist;
@@ -67,6 +71,8 @@ struct Partition final : QueueListener, PlayerListener, MixerListener {
 		  AudioFormat configured_audio_format,
 		  const ReplayGainConfig &replay_gain_config);
 
+	~Partition() noexcept;
+
 	void EmitGlobalEvent(unsigned mask) {
 		global_events.OrMask(mask);
 	}