Migrate test block 8 to Dart 2.0.

tests/corelib/for_in_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.
-
-import "package:expect/expect.dart";
-
-class ForInTest {
-  static testMain() {
-    testSimple();
-    testBreak();
-    testContinue();
-    testClosure();
-  }
-
-  static Set<int> getSmallSet() {
-    Set<int> set = new Set<int>();
-    set.add(1);
-    set.add(2);
-    set.add(4);
-    return set;
-  }
-
-  static void testSimple() {
-    Set<int> set = getSmallSet();
-    int count = 0;
-    for (final i in set) {
-      count += i;
-    }
-    Expect.equals(7, count);
-
-    count = 0;
-    for (var i in set) {
-      count += i;
-    }
-    Expect.equals(7, count);
-
-    count = 0;
-    for (int i in set) {
-      count += i;
-    }
-    Expect.equals(7, count);
-
-    count = 0;
-    for (final int i in set) {
-      count += i;
-    }
-    Expect.equals(7, count);
-
-    count = 0;
-    int i = 0;
-    Expect.equals(false, set.contains(i)); // Used to test [i] after loop.
-    for (i in set) {
-      count += i;
-    }
-    Expect.equals(7, count);
-    Expect.equals(true, set.contains(i));
-    // The default implementation of [Set] preserves order.
-    Expect.equals(4, i);
-  }
-
-  static void testBreak() {
-    Set<int> set = getSmallSet();
-    int count = 0;
-    for (final i in set) {
-      if (i == 4) break;
-      count += i;
-    }
-    Expect.equals(true, count < 4);
-  }
-
-  static void testContinue() {
-    Set<int> set = getSmallSet();
-    int count = 0;
-    for (final i in set) {
-      if (i < 4) continue;
-      count += i;
-    }
-    Expect.equals(4, count);
-  }
-
-  static void testClosure() {
-    Set<int> set = getSmallSet();
-    List<Function> closures = new List(set.length);
-    int index = 0;
-    for (var i in set) {
-      closures[index++] = () => i;
-    }
-
-    Expect.equals(index, set.length);
-    Expect.equals(7, closures[0]() + closures[1]() + closures[2]());
-  }
-}
-
-main() {
-  ForInTest.testMain();
-}