Update tests.

tests/html/postmessage_structured_test.dart

Index: tests/html/postmessage_structured_test.dart
diff --git a/tests/html/postmessage_structured_test.dart b/tests/html/postmessage_structured_test.dart
index fbba34b6f63cdaaedd00ca5c1c66c959f8c93e50..3cc6f6189a14949ef6087303a12ff99b41e4c7a6 100644
--- a/tests/html/postmessage_structured_test.dart
+++ b/tests/html/postmessage_structured_test.dart
@@ -137,7 +137,7 @@ main() {
   });
 
   group('typed_arrays', () {
-    var array_buffer = new ByteBuffer(16);
+    var array_buffer = new Uint8List(16);
     var view_a = new Float32List.view(array_buffer, 0, 4);
     var view_b = new Uint8List.view(array_buffer, 1, 13);
     var typed_arrays_list = [view_a, array_buffer, view_b];