Redo StreamTransformers so they work with Stack traces.

sdk/lib/async/async_error.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.
 
 part of dart.async;
 
 final Expando _stackTraceExpando = new Expando("asynchronous error");
 
 void _attachStackTrace(o, st) {
   if (o == null || o is bool || o is num || o is String) return;
   _stackTraceExpando[o] = st;
 }
 
 /**
- * *This is an experimental API.*
+ * *DEPRECATED*. Use explicit stack trace arguments instead.
  *
  * Get the [StackTrace] attached to [o].
  *
  * If object [o] was thrown and caught in a dart:async method, a [StackTrace]
  * object was attached to it. Use [getAttachedStackTrace] to get that object.
  *
  * Returns [null] if no [StackTrace] was attached.
  */
+@deprecated
 getAttachedStackTrace(o) {
   if (o == null || o is bool || o is num || o is String) return null;
   return _stackTraceExpando[o];
 }
 
 // TODO(floitsch): should we make this an Error class? Probably depends, if we
 // want to make the class public.
 class _AsyncError {
   final error;
   final StackTrace stackTrace;
@@ skipping 11 matching lines @@
 
     // Clear the attached stack trace.
     _attachStackTrace(error, null);
 
     if (trace != null) {
       result += "\nStack Trace:\n$trace";
     }
     return result;
   }
 }