Redo StreamTransformers so they work with Stack traces.

sdk/lib/async/async_error.dart

Index: sdk/lib/async/async_error.dart
diff --git a/sdk/lib/async/async_error.dart b/sdk/lib/async/async_error.dart
index 6cea8a57d013addc5831ccb0d129e14697e56030..687aad08aac9f2d7ae4d9bc6fdb572a2ab36a800 100644
--- a/sdk/lib/async/async_error.dart
+++ b/sdk/lib/async/async_error.dart
@@ -12,7 +12,7 @@ void _attachStackTrace(o, st) {
 }
 
 /**
- * *This is an experimental API.*
+ * *DEPRECATED*. Use explicit stack trace arguments instead.
  *
  * Get the [StackTrace] attached to [o].
  *
@@ -21,6 +21,7 @@ void _attachStackTrace(o, st) {
  *
  * 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];