Use isolate schedule immediate. Update embedder.

Source/bindings/dart/DartController.cpp

Index: Source/bindings/dart/DartController.cpp
diff --git a/Source/bindings/dart/DartController.cpp b/Source/bindings/dart/DartController.cpp
index 7890130f63e4ac3bdf5df39313e70033bb3914bc..0cf73c637960fdc10ce6fb0558051f7a42c124c3 100644
--- a/Source/bindings/dart/DartController.cpp
+++ b/Source/bindings/dart/DartController.cpp
@@ -201,7 +201,24 @@ Dart_Isolate DartController::createIsolate(const char* scriptURL, const char* en
         (isDOMEnabled ?  "_printClosure" : "_pureIsolatePrintClosure");
     copyValue(html, printClosure, "dart:_collection-dev", 0, "_printClosure");
     copyValue(html, isDOMEnabled ? "_timerFactoryClosure" : "_pureIsolateTimerFactoryClosure", "dart:async", "_TimerFactory", "_factory");
-    copyValue(html, isDOMEnabled ? "_scheduleImmediateClosure" : "_pureIsolateScheduleImmediateClosure", "dart:async", "_ScheduleImmediate", "_closure");
+    if (isDOMEnabled) {
+        copyValue(html, "_scheduleImmediateClosure", "dart:async", "_ScheduleImmediate", "_closure");
+    } else {
+        // Use the VM implementation (from dart:isolate) for scheduleImmediate.
+        Dart_Handle isolateLibrary = Dart_LookupLibrary(Dart_NewStringFromCString("dart:isolate"));
+        ASSERT(!Dart_IsError(isolateLibrary));
+
+        Dart_Handle value = Dart_Invoke(isolateLibrary, Dart_NewStringFromCString("_getIsolateScheduleImmediateClosure"), 0, 0);
+        ASSERT(!Dart_IsError(value));
+
+        Dart_Handle library = Dart_LookupLibrary(Dart_NewStringFromCString("dart:async"));
+        ASSERT(!Dart_IsError(library));
+
+        Dart_Handle target = Dart_GetType(library, Dart_NewStringFromCString("_ScheduleImmediate"), 0, 0);
+        ASSERT(!Dart_IsError(target));
+
+        Dart_SetField(target, Dart_NewStringFromCString("_closure"), value);
+    }
     copyValue(html, isDOMEnabled ? "_uriBaseClosure" : "_pureIsolateUriBaseClosure", "dart:core", 0, "_uriBaseClosure");
 
     if (isDOMEnabled) {