Roll Observatory packages and add a roll script

analyzer/lib/src/generated/testing/token_factory.dart

-// Copyright (c) 2014, 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.
-
-// This code was auto-generated, is not intended to be edited, and is subject to
-// significant change. Please see the README file for more information.
-
-library engine.testing.token_factory;
-
-import 'package:analyzer/src/generated/scanner.dart';
-
-/**
- * A set of utility methods that can be used to create tokens.
- */
-class TokenFactory {
-  static Token tokenFromKeyword(Keyword keyword) =>
-      new KeywordToken(keyword, 0);
-
-  static Token tokenFromString(String lexeme) =>
-      new StringToken(TokenType.STRING, lexeme, 0);
-
-  static Token tokenFromType(TokenType type) => new Token(type, 0);
-
-  static Token tokenFromTypeAndString(TokenType type, String lexeme) =>
-      new StringToken(type, lexeme, 0);
-}