Roll Observatory packages and add a roll script

packages/intl/test/data_directory.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.
+
+/**
+ * A utility function for test and tools that compensates (at least for very
+ * simple cases) for file-dependent programs being run from different
+ * directories. The important cases are
+ *   - running in the directory that contains the test itself, i.e.
+ *    test/ or a sub-directory.
+ *   - running in root of this package, which is where the editor and bots will
+ *   run things by default
+ */
+library data_directory;
+
+import "dart:io";
+import "package:path/path.dart" as path;
+
+String get dataDirectory {
+  return path.join(intlDirectory, datesRelativeToIntl);
+}
+
+/// Returns whether [dir] is the root of the `intl` package. We validate that it
+/// is by looking for a pubspec file with the entry `name: intl`.
+bool _isIntlRoot(String dir) {
+  var file = new File(path.join(dir, 'pubspec.yaml'));
+  if (!file.existsSync()) return false;
+  return file.readAsStringSync().contains('name: intl\n');
+}
+
+String get intlDirectory {
+  var dir = path.fromUri(Platform.script);
+  var root = path.rootPrefix(dir);
+
+  while (dir != root) {
+    if (_isIntlRoot(dir)) return dir;
+    dir = path.dirname(dir);
+  }
+  throw new UnsupportedError(
+      'Cannot find the root directory of the `intl` package.');
+}
+
+String get datesRelativeToIntl => path.join('lib', 'src', 'data', 'dates');