anchor.diff:                  "--out=$output",
                   file];
   
  -  if(liveTypeAnalysis) {
  -    args.add('--enable-native-live-type-analysis');
  +  if(liveTypeAnalysis == false) {
  +    args.add('--disable-native-live-type-analysis');
     }
   
     if(rejectDeprecatedFeatures) {
  
positive.code: 
  Task createDart2JsTask(List<String> inputs, {String output: null,
    String packageRoot: null, bool minify: false, bool allowUnsafeEval: true,
    bool liveTypeAnalysis: false, rejectDeprecatedFeatures: false}) {
    return new Task.async((context) {
      final futureFuncs = inputs
          .map((p) => () => _dart2js(context, p,
  
negative.code: 
  Future<bool> _dart2js(TaskContext ctx, String file, {String output: null,
    String packageRoot: null, bool minify: false, bool allowUnsafeEval: true,
    bool liveTypeAnalysis: true, bool rejectDeprecatedFeatures: false}) {
  
    if(output == null) {
      output = "${file}.js";
  