- Add a math library. Currently it mostly matches the Math class in dart:core.

tests/lib/math/low_test.dart

Index: tests/lib/math/low_test.dart
===================================================================
--- tests/lib/math/low_test.dart	(revision 0)
+++ tests/lib/math/low_test.dart	(revision 0)
@@ -0,0 +1,31 @@
+// Copyright (c) 2012, 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 default PRNG does uniformly distribute values when not using
+// a power of 2.
+
+// Library tag to allow Dartium to run the test.
+#library("low_test.dart");
+
+#import("dart:math");
+
+void main() {
+  var n = (2 * (1<<32)) ~/ 3;
+  var n2 = n ~/ 2;
+  
+  var iterations = 200000;
+
+  var prng = new Random();
+
+  var low = 0;
+  for (var i = 0; i < iterations; i++) {
+    if (prng.nextInt(n) < n2) {
+      low++;
+    }
+  }
+  
+  var diff = (low - (iterations ~/ 2)).abs();
+  print("$low, $diff");
+  Expect.isTrue(diff < (iterations ~/ 20)); 
+}