fix strong mode errors for 1.19.0-dev.4.0

lib/src/delegate/future.dart

Index: lib/src/delegate/future.dart
diff --git a/lib/src/delegate/future.dart b/lib/src/delegate/future.dart
index 8b81076b247fa585d316bb5273089987e7b18201..012fa99065455630846323085459abff2253b105 100644
--- a/lib/src/delegate/future.dart
+++ b/lib/src/delegate/future.dart
@@ -27,7 +27,7 @@ class DelegatingFuture<T> implements Future<T> {
   Future<T> catchError(Function onError, {bool test(Object error)}) =>
     _future.catchError(onError, test: test);
 
-  Future/*<S>*/ then/*<S>*/(/*=S*/ onValue(T value), {Function onError}) =>
+  Future/*<S>*/ then/*<S>*/(onValue(T value), {Function onError}) =>
     _future.then(onValue, onError: onError);

[Jennifer Messerly, 2016/08/16 22:36:24]

fyi -- probably want to pass /*<S>*/ explicitly here.

and we'll need to implement the custom Future inference, so this method gets as
good of inference when people call it as Future<T> would. With those changes,
this should work as well as built in Future.then

[keertip, 2016/08/18 17:51:06]

Done.

 
   Future<T> whenComplete(action()) => _future.whenComplete(action);