Fix bug in native message writer, the GetMarkedCObjectMark method was shifting teh value incorrectl…

vm/dart_api_message.cc

 // Copyright (c) 2012, 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.
 
 #include "vm/dart_api_message.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 
 namespace dart {
 
@@ skipping 386 matching lines @@
 }
 
 
 bool ApiMessageWriter::IsCObjectMarked(Dart_CObject* object) {
   return (object->type & kDartCObjectMarkMask) != 0;
 }
 
 
 intptr_t ApiMessageWriter::GetMarkedCObjectMark(Dart_CObject* object) {
   ASSERT(IsCObjectMarked(object));
-  intptr_t mark_value = ((object->type & kDartCObjectMarkMask) >> 3);
+  intptr_t mark_value =
+      ((object->type & kDartCObjectMarkMask) >> kDartCObjectTypeBits);
   // An offset was added to object id for making marking object id 0 possible.
   return mark_value - kDartCObjectMarkOffset;
 }
 
 
 void ApiMessageWriter::UnmarkAllCObjects(Dart_CObject* object) {
   if (!IsCObjectMarked(object)) return;
   UnmarkCObject(object);
   if (object->type == Dart_CObject::kArray) {
     for (int i = 0; i < object->value.as_array.length; i++) {
@@ skipping 145 matching lines @@
 }
 
 
 void ApiMessageWriter::WriteCMessage(Dart_CObject* object) {
   WriteCObject(object);
   UnmarkAllCObjects(object);
   FinalizeBuffer();
 }
 
 }  // namespace dart