Remove AsyncError with Expando.

tests/lib/async/futures_test.dart

Index: tests/lib/async/futures_test.dart
diff --git a/tests/lib/async/futures_test.dart b/tests/lib/async/futures_test.dart
index 7ae1d7eaaf680b3cf7082d19979f338e2535f94e..9dc9b1c26998fdf1b44a32d581d78ba5f7362053 100644
--- a/tests/lib/async/futures_test.dart
+++ b/tests/lib/async/futures_test.dart
@@ -53,8 +53,8 @@ Future testWaitWithSingleError() {
 
   return Future.wait(futures).then((_) {
     throw 'incorrect error';
-  }).catchError((e) {
-    Expect.equals('correct error', e.error);
+  }).catchError((error) {
+    Expect.equals('correct error', error);
   });
 }
 
@@ -69,8 +69,8 @@ Future testWaitWithMultipleErrors() {
 
   return Future.wait(futures).then((_) {
     throw 'incorrect error 2';
-  }).catchError((e) {
-    Expect.equals('correct error', e.error);
+  }).catchError((error) {
+    Expect.equals('correct error', error);
   });
 }
 
@@ -96,8 +96,8 @@ Future testForEachWithException() {
     return new Future.immediate(null);
   }).then((_) {
     throw 'incorrect exception';
-  }).catchError((e) {
-    Expect.equals('correct exception', e.error);
+  }).catchError((error) {
+    Expect.equals('correct exception', error);
   });
 }