port polymer data binding tests

pkg/polymer/lib/job.dart

 // 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.
 
 library polymer.job;
 
 import 'dart:async' show Timer;
 
 /**
  * Invoke [callback] in [wait], unless the job is re-registered,
@@ skipping 10 matching lines @@
   } else {
     job = new Job();
   }
   job.go(callback, wait);
   return job;
 }
 
 // TODO(jmesserly): it isn't clear to me what is supposed to be public API here.
 // Or what name we should use. "Job" is awfully generic.
 // (The type itself is not exported in Polymer.)
+// Remove this type in favor of Timer?
 class Job {
   Function _callback;
   Timer _timer;
 
   void go(void callback(), Duration wait) {
     this._callback = callback;
     _timer = new Timer(wait, complete);
   }
 
   void stop() {
     if (_timer != null) {
       _timer.cancel();
       _timer = null;
     }
   }
 
   void complete() {
     if (_timer != null) {
       stop();
       _callback();
     }
   }
 }