Remove deprecated parts of dart:async.

pkg/polymer/lib/src/build/runner.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.
 
 /**
  * Definitions used to run the polymer linter and deploy tools without using
  * pub serve or pub deploy.
  */
 library polymer.src.build.runner;
 
@@ skipping 156 matching lines @@
   addAssets(options.currentPackage, 'web');
   if (options.transformTests) addAssets(options.currentPackage, 'test');
 
   barback.updateSources(assets);
 }
 
 /** Attach error listeners on [barback] so we can report errors. */
 void _attachListeners(Barback barback) {
   // Listen for errors and results
   barback.errors.listen((e) {
-    var trace = getAttachedStackTrace(e);
+    var trace = null;
+    if (e is Error) trace = e.stackTrace;
     if (trace != null) {
       print(Trace.format(trace));
     }
     print('error running barback: $e');
     exit(1);
   });
 
   barback.results.listen((result) {
     if (!result.succeeded) {
       print("build failed with errors: ${result.errors}");
@@ skipping 115 matching lines @@
 Future _copyFile(String inpath, String outpath) {
   _ensureDir(path.dirname(outpath));
   return new File(inpath).openRead().pipe(new File(outpath).openWrite());
 }
 
 /** Write contents of an [asset] into a file at [filepath]. */
 Future _writeAsset(String filepath, Asset asset) {
   _ensureDir(path.dirname(filepath));
   return asset.read().pipe(new File(filepath).openWrite());
 }