Migrate test block 3 to Dart 2.0.

tests/corelib_2/collection_from_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library collection.from.test;
 
 import "package:expect/expect.dart";
 import 'dart:collection' show Queue;
 
 class CollectionFromTest {
@@ skipping 24 matching lines @@
       otherSum += e;
     });
     Expect.equals(4 + 2 + 1, otherSum);
     Expect.equals(otherSum, initialSum);
   }
 }
 
 main() {
   CollectionFromTest.testMain();
 }