Roll Observatory packages and add a roll script

packages/unittest/lib/html_individual_config.dart

 // Copyright (c) 2013, 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 unit test library for running groups of tests in a browser, instead of the
 /// entire test file. This is especially used for large tests files that have
 /// many subtests, so we can mark groups as failing at a finer granularity than
 /// the entire test file.
 ///
 /// To use, import this file, and call [useHtmlIndividualConfiguration] at the
@@ skipping 28 matching lines @@
   }
 }
 
 void useHtmlIndividualConfiguration([bool isLayoutTest = false]) {
   unittest.unittestConfiguration =
       isLayoutTest ? _singletonLayout : _singletonNotLayout;
 }
 
 final _singletonLayout = new HtmlIndividualConfiguration(true);
 final _singletonNotLayout = new HtmlIndividualConfiguration(false);