N3191: C++ Timeout Specification

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@119909 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/thread b/include/thread
index fe671b2..abb56f4 100644
--- a/include/thread
+++ b/include/thread
@@ -406,10 +406,10 @@
 template <class _Duration>
 inline _LIBCPP_INLINE_VISIBILITY
 void
-sleep_until(const chrono::time_point<chrono::monotonic_clock, _Duration>& __t)
+sleep_until(const chrono::time_point<chrono::steady_clock, _Duration>& __t)
 {
     using namespace chrono;
-    sleep_for(__t - monotonic_clock::now());
+    sleep_for(__t - steady_clock::now());
 }
 
 inline _LIBCPP_INLINE_VISIBILITY