Remove deprecated parts of dart:async.

pkg/scheduled_test/lib/src/schedule_error.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 schedule_error;
 
 import 'dart:async';
 
 import 'package:stack_trace/stack_trace.dart';
 
@@ skipping 29 matching lines @@
 
   int get hashCode => schedule.hashCode ^ task.hashCode ^ queue.hashCode ^
       _stateWhenDetected.hashCode ^ error.hashCode ^ stackTrace.hashCode;
 
   /// Creates a new [ScheduleError] wrapping [error]. The metadata in
   /// [ScheduleError]s will be preserved.
   factory ScheduleError.from(Schedule schedule, error,
                              {StackTrace stackTrace}) {
     if (error is ScheduleError) return error;
 
-    var attachedTrace = getAttachedStackTrace(error);
-    if (attachedTrace != null) {
+    if (stackTrace == null && error is Error) {
       // Overwrite the explicit stack trace, because it probably came from a
       // rethrow in the first place.
-      stackTrace = attachedTrace;
+      stackTrace = error.stackTrace;
     }
 
     if (stackTrace == null) stackTrace = new Trace.current();
     return new ScheduleError(schedule, error, stackTrace);
   }
 
   // TODO(floitsch): restore StackTrace type when it has been integrated into
   // the core libraries.
   ScheduleError(Schedule schedule, error, var stackTrace)
       : error = error,
@@ skipping 44 matching lines @@
       result.write("\n\n");
       result.writeln("Pending out-of-band callbacks:");
       for (var callback in pendingCallbacks) {
         result.writeln(prefixLines(callback.toString(), firstPrefix: "* "));
       }
     }
 
     return result.toString().trim();
   }
 }