Roll Observatory packages and add a roll script

analyzer/lib/src/string_source.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.
-
-library analyzer.string_source;
-
-import 'generated/engine.dart' show TimestampedData;
-import 'generated/source.dart';
-
-/// An implementation of [Source] that's based on an in-memory Dart string.
-class StringSource extends Source {
-  final String _contents;
-  final String fullName;
-  final int modificationStamp;
-
-  StringSource(this._contents, this.fullName)
-      : modificationStamp = new DateTime.now().millisecondsSinceEpoch;
-
-  TimestampedData<String> get contents =>
-      new TimestampedData(modificationStamp, _contents);
-
-  String get encoding =>
-      throw new UnsupportedError("StringSource doesn't support " "encoding.");
-
-  int get hashCode => _contents.hashCode ^ fullName.hashCode;
-
-  bool get isInSystemLibrary => false;
-
-  String get shortName => fullName;
-
-  @override
-  Uri get uri =>
-      throw new UnsupportedError("StringSource doesn't support uri.");
-
-  UriKind get uriKind =>
-      throw new UnsupportedError("StringSource doesn't support " "uriKind.");
-
-  bool operator ==(Object object) {
-    if (object is StringSource) {
-      StringSource ssObject = object;
-      return ssObject._contents == _contents && ssObject.fullName == fullName;
-    }
-    return false;
-  }
-
-  bool exists() => true;
-
-  Uri resolveRelativeUri(Uri relativeUri) => throw new UnsupportedError(
-      "StringSource doesn't support resolveRelative.");
-}