Add mojo/c/system/{time.h,wait.h}.

mojo/public/c/system/handle.h

Index: mojo/public/c/system/handle.h
diff --git a/mojo/public/c/system/handle.h b/mojo/public/c/system/handle.h
index 73a7ed814f2ad34155a524e80ec3975de293d216..2751886eaef75bb91a6c86dbe499fcd0f4fe941b 100644
--- a/mojo/public/c/system/handle.h
+++ b/mojo/public/c/system/handle.h
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// This file contains the handle-related definitions/declarations.
+// This file contains Mojo system handle-related declarations/definitions.
 //
 // Note: This header should be compilable as C.
 
@@ -12,6 +12,7 @@
 #include <stdint.h>
 
 #include "mojo/public/c/system/macros.h"
+#include "mojo/public/c/system/result.h"
 
 // |MojoHandle|: Handles to Mojo objects.
 //   |MOJO_HANDLE_INVALID| - A value that is never a valid handle.
@@ -54,4 +55,24 @@ struct MOJO_ALIGNAS(4) MojoHandleSignalsState {
 MOJO_STATIC_ASSERT(sizeof(MojoHandleSignalsState) == 8,
                    "MojoHandleSignalsState has wrong size");
 
+#ifdef __cplusplus

[jamesr, 2016/03/11 18:36:42]

maybe this should go in macros.h - i forsee it being typed a lot as functions
are peeled out of functions.h

[viettrungluu, 2016/03/11 20:38:31]

Will think about doing so (separately).

+extern "C" {
+#endif
+
+// Closes the given |handle|.
+//
+// Returns:
+//   |MOJO_RESULT_OK| on success.
+//   |MOJO_RESULT_INVALID_ARGUMENT| if |handle| is not a valid handle.
+//
+// Concurrent operations on |handle| may succeed (or fail as usual) if they
+// happen before the close, be cancelled with result |MOJO_RESULT_CANCELLED| if
+// they properly overlap (this is likely the case with |MojoWait()|, etc.), or
+// fail with |MOJO_RESULT_INVALID_ARGUMENT| if they happen after.
+MojoResult MojoClose(MojoHandle handle);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
 #endif  // MOJO_PUBLIC_C_SYSTEM_HANDLE_H_