Roll Observatory packages and add a roll script

packages/utf/test/utf8_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 utf.utf8_test;
+
+import "package:expect/expect.dart";
+import "package:utf/utf.dart";
+
+String decode(List<int> bytes) => decodeUtf8(bytes);
+
+main() {
+  // Google favorite: "Îñţérñåţîöñåļîžåţîờñ".
+  String string = decode([0xc3, 0x8e, 0xc3, 0xb1, 0xc5, 0xa3, 0xc3, 0xa9, 0x72,
+                          0xc3, 0xb1, 0xc3, 0xa5, 0xc5, 0xa3, 0xc3, 0xae, 0xc3,
+                          0xb6, 0xc3, 0xb1, 0xc3, 0xa5, 0xc4, 0xbc, 0xc3, 0xae,
+                          0xc5, 0xbe, 0xc3, 0xa5, 0xc5, 0xa3, 0xc3, 0xae, 0xe1,
+                          0xbb, 0x9d, 0xc3, 0xb1]);
+  Expect.stringEquals("Îñţérñåţîöñåļîžåţîờñ", string);
+
+  // Blueberry porridge in Danish: "blåbærgrød".
+  string = decode([0x62, 0x6c, 0xc3, 0xa5, 0x62, 0xc3, 0xa6, 0x72, 0x67, 0x72,
+                   0xc3, 0xb8, 0x64]);
+  Expect.stringEquals("blåbærgrød", string);
+
+  // "சிவா அணாமாைல", that is "Siva Annamalai" in Tamil.
+  string = decode([0xe0, 0xae, 0x9a, 0xe0, 0xae, 0xbf, 0xe0, 0xae, 0xb5, 0xe0,
+                   0xae, 0xbe, 0x20, 0xe0, 0xae, 0x85, 0xe0, 0xae, 0xa3, 0xe0,
+                   0xae, 0xbe, 0xe0, 0xae, 0xae, 0xe0, 0xae, 0xbe, 0xe0, 0xaf,
+                   0x88, 0xe0, 0xae, 0xb2]);
+  Expect.stringEquals("சிவா அணாமாைல", string);
+
+  // "िसवा अणामालै", that is "Siva Annamalai" in Devanagari.
+  string = decode([0xe0, 0xa4, 0xbf, 0xe0, 0xa4, 0xb8, 0xe0, 0xa4, 0xb5, 0xe0,
+                   0xa4, 0xbe, 0x20, 0xe0, 0xa4, 0x85, 0xe0, 0xa4, 0xa3, 0xe0,
+                   0xa4, 0xbe, 0xe0, 0xa4, 0xae, 0xe0, 0xa4, 0xbe, 0xe0, 0xa4,
+                   0xb2, 0xe0, 0xa5, 0x88]);
+  Expect.stringEquals("िसवा अणामालै", string);
+
+  // DESERET CAPITAL LETTER BEE, unicode 0x10412(0xD801+0xDC12)
+  // UTF-8: F0 90 90 92
+  string = decode([0xf0, 0x90, 0x90, 0x92]);
+  Expect.equals(string.length, 2);
+  Expect.equals("𐐒".length, 2);
+  Expect.stringEquals("𐐒", string);
+
+  // TODO(ahe): Add tests of bad input.
+}