Add Dart_PostPriority function to dart_api, and use it in runAsync to schedule immediate events in …

runtime/bin/dartutils.cc

Index: runtime/bin/dartutils.cc
diff --git a/runtime/bin/dartutils.cc b/runtime/bin/dartutils.cc
index eabd4f37a581cdb020a182a0aa3757499470ce99..37b12507094c0053c4cfd97be553bb68d59ed0b8 100644
--- a/runtime/bin/dartutils.cc
+++ b/runtime/bin/dartutils.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2013, 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.
 
@@ -683,6 +683,15 @@ Dart_Handle DartUtils::PrepareForScriptLoading(const char* package_root,
   DART_CHECK_VALID(Dart_Invoke(
       async_lib, NewString("_setTimerFactoryClosure"), 1, args));
 
+  Dart_Handle enqueue_immediate_closure =
+      Dart_Invoke(io_lib,
+                  NewString("_getEnqueueImmediateFactoryClosure"),
+                  0,
+                  NULL);
+  args[0] = enqueue_immediate_closure;
+  DART_CHECK_VALID(Dart_Invoke(
+      async_lib, NewString("_setEnqueueImmediateFactoryClosure"), 1, args));
+
   // Setup the corelib 'Uri.base' getter.
   Dart_Handle uri_base = Dart_Invoke(
       builtin_lib, NewString("_getUriBaseClosure"), 0, NULL);