system/Clock: GetProcessUptimeS() returns std::chrono::duration

src/system/Clock.cxx

@@ -23,7 +23,7 @@
 #include <windows.h>
 
 gcc_const
-static unsigned
+static std::chrono::seconds
 DeltaFileTimeS(FILETIME a, FILETIME b)
 {
 	ULARGE_INTEGER a2, b2;
@@ -31,10 +31,10 @@ DeltaFileTimeS(FILETIME a, FILETIME b)
 	b2.HighPart = b.dwHighDateTime;
 	a2.LowPart = a.dwLowDateTime;
 	a2.HighPart = a.dwHighDateTime;
-	return (a2.QuadPart - b2.QuadPart) / 10000000;
+	return std::chrono::seconds((a2.QuadPart - b2.QuadPart) / 10000000);
 }
 
-unsigned
+std::chrono::seconds
 GetProcessUptimeS()
 {
 	FILETIME creation_time, exit_time, kernel_time, user_time, now;

src/system/Clock.hxx

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2018 The Music Player Daemon Project
+ * Copyright 2003-2019 The Music Player Daemon Project
  * http://www.musicpd.org
  *
  * This program is free software; you can redistribute it and/or modify
@@ -22,13 +22,15 @@
 
 #include "util/Compiler.h"
 
+#include <chrono>
+
 #ifdef _WIN32
 
 /**
  * Returns the uptime of the current process in seconds.
  */
 gcc_pure
-unsigned
+std::chrono::seconds
 GetProcessUptimeS();
 
 #endif