convert isolate TestFramework from Promise Future

tests/isolate/src/TestFramework.dart

Index: tests/isolate/src/TestFramework.dart
diff --git a/tests/isolate/src/TestFramework.dart b/tests/isolate/src/TestFramework.dart
index 97162ba279790417dcf6750567bf4728d8169d2a..67e669578601d39829e6c8ea72ff8142e5733fc6 100644
--- a/tests/isolate/src/TestFramework.dart
+++ b/tests/isolate/src/TestFramework.dart
@@ -174,16 +174,17 @@ class TestExpectation {
     testCase.tearDown();
   }
 
-  Promise completes(var promise) {
-    if (!(promise is Promise || promise is Future)) {
+  Future completes(var future) {
+    if (!(future is Promise || future is Future)) {
       // TODO(mattsh) - remove this hack once we finish conversion of
       // Promise to Future
       throw "must pass Promise or Future to TestFramework.completes";
     }
-
-    Promise result = new TestPromise(this);
-    promise.then((value) { result.complete(value); });
-    return result;
+    Completer completer = new Completer();
+    future.then(runs1((value) {
+      completer.complete(value);
+    }));
+    return completer.future;
   }
 
   Promise completesWithValue(Promise promise, var expected) {