Add base 64 encoding to the crypto library utils.

tests/lib/crypto/base64_test.dart

+// 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.
+
+// Library tag to allow the test to run on Dartium.
+#library('base64_test');
+
+#import("dart:crypto");
+
+// Data from http://tools.ietf.org/html/rfc4648.
+var inputs =
+    const [ '', 'f', 'fo', 'foo', 'foob', 'fooba', 'foobar' ];
+var results =
+    const [ '', 'Zg==', 'Zm8=', 'Zm9v', 'Zm9vYg==', 'Zm9vYmE=', 'Zm9vYmFy' ];

[Søren Gjesse, 2012/05/30 13:40:08]

There is a longer example in tests/standalone/crypto/base64_test.dart

[Mads Ager (google), 2012/05/30 15:16:10]

Thanks!

+
+void main() {
+  for (var i = 0; i < inputs.length; i++) {
+    var enc = CryptoUtils.bytesToBase64(inputs[i].charCodes());
+    Expect.equals(results[i], enc);
+  }
+}