Let completers complete in the zone they were constructed in.

sdk/lib/async/future_impl.dart

Index: sdk/lib/async/future_impl.dart
diff --git a/sdk/lib/async/future_impl.dart b/sdk/lib/async/future_impl.dart
index be0b7a23229fff9d0acee3ff592698f11332e542..1e644d581250eb4267e2e626b7806b5ed7d11bf8 100644
--- a/sdk/lib/async/future_impl.dart
+++ b/sdk/lib/async/future_impl.dart
@@ -23,8 +23,8 @@ abstract class _Completer<T> implements Completer<T> {
     if (_isComplete) throw new StateError("Future already completed");
     _isComplete = true;
     _FutureImpl futureImpl = future;
-    futureImpl._zone.cancelCallbackExpectation();
     _setFutureValue(value);
+    futureImpl._zone.cancelCallbackExpectation();
   }
 
   void completeError(Object error, [Object stackTrace = null]) {
@@ -35,12 +35,8 @@ abstract class _Completer<T> implements Completer<T> {
       _attachStackTrace(error, stackTrace);
     }
     _FutureImpl futureImpl = future;
-    if (futureImpl._inSameErrorZone(_Zone.current)) {
-      futureImpl._zone.cancelCallbackExpectation();
-      _setFutureError(error);
-    } else {
-      _Zone.current.handleUncaughtError(error);
-    }
+    _setFutureError(error);
+    futureImpl._zone.cancelCallbackExpectation();

[Lasse Reichstein Nielsen, 2013/07/05 19:00:07]

Is this too early if _setFutureError is async? We don't want the zone to go away
before the future is completed.

Should the future be the one to decide when it has received its callback,
instead of the controller doing it?

[floitsch, 2013/07/08 10:45:51]

Moved it down to _setFutureValue and _setFutureError.
Ideally it would be the future that decides, but that would require some
refactoring.

   }
 
   bool get isCompleted => _isComplete;