Mojo: add support for disallowing sync calls for a process.

mojo/public/c/system/functions.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file contains basic functions common to different Mojo system APIs.
 //
 // Note: This header should be compilable as C.
 
 #ifndef MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_
 #define MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_
@@ skipping 188 matching lines @@
 //     |MojoWatch()|. Only the watch corresponding to this context will be
 //     cancelled.
 //
 // Returns:
 //     |MOJO_RESULT_OK| if the watch corresponding to |context| was cancelled.
 //     |MOJO_RESULT_INVALID_ARGUMENT| if no watch was registered with |context|
 //         for the given |handle|, or if |handle| is invalid.
 MOJO_SYSTEM_EXPORT MojoResult
 MojoCancelWatch(MojoHandle handle, uintptr_t context);
 
+// Retrieves system properties. See the documentation for |MojoPropertyType| for
+// supported property types and their corresponding output value type.
+//
+// Returns:
+//     |MOJO_RESULT_OK| on success.
+//     |MOJO_RESULT_INVALID_ARGUMENT| if |type| is not recognized. In this case,
+//         |value| is untouched.
+MOJO_SYSTEM_EXPORT MojoResult MojoGetProperty(MojoPropertyType type,
+                                              void* value);
+
 #ifdef __cplusplus
 }  // extern "C"
 #endif
 
 #endif  // MOJO_PUBLIC_C_SYSTEM_FUNCTIONS_H_