Add a sleep function to dart:io

runtime/bin/utils_win.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include <errno.h>  // NOLINT
 #include <time.h>  // NOLINT
 
@@ skipping 123 matching lines @@
   // 100-nanosecond intervals since January 1, 1601.
   union TimeStamp {
     FILETIME ft_;
     int64_t t_;
   };
   TimeStamp time;
   GetSystemTimeAsFileTime(&time.ft_);
   return (time.t_ - kTimeEpoc) / kTimeScaler;
 }
 
+void TimerUtils::Sleep(int64_t millis) {
+  ::Sleep(millis);
+}
+
 #endif  // defined(TARGET_OS_WINDOWS)