Roll Observatory packages and add a roll script

packages/path/test/path_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.
+
+import 'package:unittest/unittest.dart';
+import 'package:path/path.dart' as path;
+
+main() {
+  group('path.Style', () {
+    test('name', () {
+      expect(path.Style.posix.name, 'posix');
+      expect(path.Style.windows.name, 'windows');
+    });
+
+    test('separator', () {
+      expect(path.Style.posix.separator, '/');
+      expect(path.Style.windows.separator, '\\');
+    });
+
+    test('toString()', () {
+      expect(path.Style.posix.toString(), 'posix');
+      expect(path.Style.windows.toString(), 'windows');
+    });
+  });
+
+  group('new Context()', () {
+    test('uses the given current directory', () {
+      var context = new path.Context(current: '/a/b/c');
+      expect(context.current, '/a/b/c');
+    });
+
+    test('uses the given style', () {
+      var context = new path.Context(style: path.Style.windows);
+      expect(context.style, path.Style.windows);
+    });
+  });
+
+  test('posix is a default Context for the POSIX style', () {
+    expect(path.posix.style, path.Style.posix);
+    expect(path.posix.current, ".");
+  });
+
+  test('windows is a default Context for the Windows style', () {
+    expect(path.windows.style, path.Style.windows);
+    expect(path.windows.current, ".");
+  });
+
+  test('url is a default Context for the URL style', () {
+    expect(path.url.style, path.Style.url);
+    expect(path.url.current, ".");
+  });
+}