db/LightSong: use std::chrono::duration for start_ms and end_ms

src/db/LightSong.hxx

@@ -20,6 +20,7 @@
 #ifndef MPD_LIGHT_SONG_HXX
 #define MPD_LIGHT_SONG_HXX
 
+#include "Chrono.hxx"
 #include "Compiler.h"
 
 #include <string>
@@ -64,15 +65,15 @@ struct LightSong {
 	time_t mtime;
 
 	/**
-	 * Start of this sub-song within the file in milliseconds.
+	 * Start of this sub-song within the file.
 	 */
-	unsigned start_ms;
+	SongTime start_time;
 
 	/**
-	 * End of this sub-song within the file in milliseconds.
+	 * End of this sub-song within the file.
 	 * Unused if zero.
 	 */
-	unsigned end_ms;
+	SongTime end_time;
 
 	gcc_pure
 	std::string GetURI() const {