Change new List(n) to return fixed length list.

tests/isolate/mandel_isolate_test.dart

Index: tests/isolate/mandel_isolate_test.dart
diff --git a/tests/isolate/mandel_isolate_test.dart b/tests/isolate/mandel_isolate_test.dart
index 292d6d63f4e4ecdcc0184ed8361f8db1f55411f6..abc4d8315215dc90259d593ce9faba1b3750dd2d 100644
--- a/tests/isolate/mandel_isolate_test.dart
+++ b/tests/isolate/mandel_isolate_test.dart
@@ -27,7 +27,7 @@ class MandelbrotState {
 
   MandelbrotState() {
     _result = new List<List<int>>(N);
-    _lineProcessedBy = new List<LineProcessorClient>.fixedLength(N);
+    _lineProcessedBy = new List<LineProcessorClient>(N);
     _sent = 0;
     _missing = N;
     _validated = new Completer<bool>();
@@ -107,7 +107,7 @@ class LineProcessorClient {
 List<int> processLine(int y) {
   double inverseN = 2.0 / N;
   double Civ = y * inverseN - 1.0;
-  List<int> result = new List<int>.fixedLength(N);
+  List<int> result = new List<int>(N);
   for (int x = 0; x < N; x++) {
     double Crv = x * inverseN - 1.5;