Dart2js async-await. Propagate stacktraces from futures.

tests/language/asyncstar_throw_in_catch_test.dart

 // Copyright (c) 2015, 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.
 
 import "dart:async";
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 
 class Tracer {
   final String expected;
@@ skipping 20 matching lines @@
     tracer.trace("a");
     await new Future.value(3);
     tracer.trace("b");
     throw "Error";
   } catch (e) {
     tracer.trace("c");
     yield 1;
     tracer.trace("d");
     yield 2;
     tracer.trace("e");
-    await new Future.error("Error2");
   } finally {
     tracer.trace("f");
   }
   tracer.trace("g");
 }
 
+foo2(Tracer tracer) async* {
+  try {
+    tracer.trace("a");
+    throw "Error";
+  } catch (error) {
+    Expect.equals("Error", error);
+    tracer.trace("b");
+    rethrow;
+  } finally {
+    tracer.trace("c");
+  }
+}
+
+foo3(Tracer tracer) async* {
+  try {
+    tracer.trace("a");
+    throw "Error";
+  } catch (error) {
+    Expect.equals("Error", error);
+    tracer.trace("b");
+    rethrow;
+  } finally {
+    tracer.trace("c");
+    yield 1;
+  }
+}
+
+runTest(test, expectedTrace, expectedError, shouldCancel) {
+  Tracer tracer = new Tracer(expectedTrace);;
+  Completer done = new Completer();
+  var subscription;
+  subscription = test(tracer).listen((event) async {
+    tracer.trace("Y");
+    if (shouldCancel) {
+      await subscription.cancel();
+      tracer.trace("C");
+      done.complete(null);
+    }
+  }, onError: (error) {
+    Expect.equals(expectedError, error);
+    tracer.trace("X");
+  }, onDone: () {
+      tracer.done();
+      done.complete(null);
+  });
+  return done.future.then((_) => tracer.done());
+}
+
 test() async {
-  Tracer tracer;
-
-  Completer foo1Done = new Completer();
-  tracer = new Tracer("abcdf");
-  var subscription;
-  subscription = foo1(tracer).listen((event) async {
-    await subscription.cancel();
-    tracer.done();
-    foo1Done.complete(null);
-  });
-  await foo1Done.future;
+  await runTest(foo1, "abcdYfC", null, true);

[floitsch, 2015/02/20 12:36:05]

This looks a change from a different CL.

[sigurdm, 2015/02/23 12:41:18]

Yes it is - I must have made a mistake during upload. But it is from
https://codereview.chromium.org/947433002/  And already comitted.

+  await runTest(foo2, "abcX", "Error", false);
+  await runTest(foo3, "abcYX", "Error", false);
 }
 
 
 void main() {
   asyncTest(test);
 }