Migrated test block 216 to Dart 2.0.

tests/lib_strong/math/random_secure_test.dart

-// Copyright (c) 2015, 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.
-
-// Test that the secure random generator does not systematically generates
-// duplicates. Note that this test is flaky by definition, since duplicates
-// can occur. They should be extremely rare, though.
-
-// Library tag to allow Dartium to run the test.
-library random_secure;
-
-import "package:expect/expect.dart";
-import 'dart:math';
-
-main() {
-  var results;
-  var rng0;
-  var rng1;
-  var checkInt = (max) {
-    var intVal0 = rng0.nextInt(max);
-    var intVal1 = rng1.nextInt(max);
-    if (max > (1 << 28)) {
-      Expect.isFalse(results.contains(intVal0));
-      results.add(intVal0);
-      Expect.isFalse(results.contains(intVal1));
-      results.add(intVal1);
-    }
-  };
-  results = [];
-  rng0 = new Random.secure();
-  for (var i = 0; i <= 32; i++) {
-    rng1 = new Random.secure();
-    checkInt(pow(2, 32));
-    checkInt(pow(2, 32 - i));
-    checkInt(1000000000);
-  }
-  var checkDouble = () {
-    var doubleVal0 = rng0.nextDouble();
-    var doubleVal1 = rng1.nextDouble();
-    Expect.isFalse(results.contains(doubleVal0));
-    results.add(doubleVal0);
-    Expect.isFalse(results.contains(doubleVal1));
-    results.add(doubleVal1);
-  };
-  results = [];
-  rng0 = new Random.secure();
-  for (var i = 0; i < 32; i++) {
-    rng1 = new Random.secure();
-    checkDouble();
-  }
-  var cnt0 = 0;
-  var cnt1 = 0;
-  rng0 = new Random.secure();
-  for (var i = 0; i < 32; i++) {
-    rng1 = new Random.secure();
-    cnt0 += rng0.nextBool() ? 1 : 0;
-    cnt1 += rng1.nextBool() ? 1 : 0;
-  }
-  Expect.isTrue((cnt0 > 0) && (cnt0 < 32));
-  Expect.isTrue((cnt1 > 0) && (cnt1 < 32));
-}