MutationObserver constructor

Implementation

factory MutationObserver(MutationCallback callback) {
  // Dummy statement to mark types as instantiated.
  JS('MutationObserver|MutationRecord', '0');

  return JS(
      'MutationObserver',
      'new(window.MutationObserver||window.WebKitMutationObserver||'
          'window.MozMutationObserver)(#)',
      convertDartClosureToJS(_wrapBinaryZone(callback), 2));
}