Redo StreamTransformers so they work with Stack traces.

tests/lib/async/stream_controller_test.dart

Index: tests/lib/async/stream_controller_test.dart
diff --git a/tests/lib/async/stream_controller_test.dart b/tests/lib/async/stream_controller_test.dart
index 8f1d26aa0da74db3b6a638ce0992892a4daee67a..be9e975e7f5c018c3698b17792227982f70af2ac 100644
--- a/tests/lib/async/stream_controller_test.dart
+++ b/tests/lib/async/stream_controller_test.dart
@@ -102,9 +102,9 @@ void testMultiController() {
   expectedEvents =
       new Events()..error("a")..add(42)..error("b")..add("foo")..close();
   actualEvents = new Events.capture(c.stream.asBroadcastStream().transform(
-      new StreamTransformer(
+      new StreamTransformer.fromHandlers(
           handleData: (v, s) { s.addError(v); },
-          handleError: (e, s) { s.add(e); },
+          handleError: (e, st, s) { s.add(e); },
           handleDone: (s) {
             s.add("foo");
             s.close();
@@ -279,9 +279,9 @@ testSingleController() {
   expectedEvents =
       new Events()..error("a")..add(42)..error("b")..add("foo")..close();
   actualEvents = new Events.capture(c.stream.transform(
-      new StreamTransformer(
+      new StreamTransformer.fromHandlers(
           handleData: (v, s) { s.addError(v); },
-          handleError: (e, s) { s.add(e); },
+          handleError: (e, st, s) { s.add(e); },
           handleDone: (s) {
             s.add("foo");
             s.close();