Make 'where' lazy.

tests/corelib/queue_test.dart

Index: tests/corelib/queue_test.dart
diff --git a/tests/corelib/queue_test.dart b/tests/corelib/queue_test.dart
index 1b91ff61c22b1a34a75d269d9549c0c64116ed46..298b1e8e48b79dd478d1969efe8cf1e13987b8bf 100644
--- a/tests/corelib/queue_test.dart
+++ b/tests/corelib/queue_test.dart
@@ -48,7 +48,7 @@ class QueueTest {
     Expect.equals(100, mapped.removeLast());
     Expect.equals(10, mapped.removeFirst());
 
-    Queue other = queue.where(is10);
+    Queue other = new Queue.from(queue.where(is10));
     checkQueue(other, 1, 10);
 
     Expect.equals(true, queue.some(is10));
@@ -98,7 +98,7 @@ class QueueTest {
       return (value > 1);
     }
 
-    other = queue.where(isGreaterThanOne);
+    other = new Queue.from(queue.where(isGreaterThanOne));
     checkQueue(other, 2, 5);
 
     testAddAll();