Partially address a FIXME in steady_clock::now()

  http://reviews.llvm.org/D4045

llvm-svn: 216949
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: c59e585126d36051c0913d432ff224ef97a8583e
diff --git a/src/chrono.cpp b/src/chrono.cpp
index 15a6f46..83661b0 100644
--- a/src/chrono.cpp
+++ b/src/chrono.cpp
@@ -46,6 +46,7 @@
     return system_clock::time_point(seconds(t));
 }
 
+#ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK
 // steady_clock
 
 const bool steady_clock::is_steady;
@@ -127,6 +128,8 @@
 }
 #endif  // __APPLE__
 
+#endif // !_LIBCPP_HAS_NO_MONOTONIC_CLOCK
+
 }
 
 _LIBCPP_END_NAMESPACE_STD