Implement cryptographically secure random numbers by using crypto.getRandomValues.

tests/lib/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;
@@ skipping 12 matching lines @@
       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(1 << 32);
-    checkInt(1 << (32 - i));
+    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));
 }