Rework Timer interface.

tests/lib/async/slow_consumer3_test.dart

 // 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.
 
 // VMOptions=--old_gen_heap_size=32
 
 library slow_consumer3_test;
 
 import 'dart:async';
 import 'dart:isolate';
@@ skipping 17 matching lines @@
     subscription = stream.listen(
       (List<int> data) {
         receivedCount += data.length;
         usedBufferSize += data.length;
         bufferedData.add(data);
         int currentBufferedDataLength = bufferedData.length;
         if (usedBufferSize > bufferSize) {
           subscription.pause();
           usedBufferSize = 0;
           int ms = data.length * 1000 ~/ bytesPerSecond;
-          new Timer(ms, (_) {
+          Duration duration = new Duration(milliseconds: ms);
+          new Timer(duration, () {
             for (int i = 0; i < currentBufferedDataLength; i++) {
               bufferedData[i] = null;
             }
             subscription.resume();
           });
         }
       },
       onDone: () { result.complete(receivedCount); });
     return result.future;
   }
@@ skipping 22 matching lines @@
   // file). If the consumer doesn't pause the data-provider it will run out of
   // heap-space.
 
   dataGenerator(100 * MB, 512 * KB)
     .pipe(new SlowConsumer(200 * MB, 3 * MB))
     .then((count) {
       port.close();
       Expect.equals(100 * MB, count);
     });
 }