Breaking changes in 'analyzer' package.

pkg/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/source.dart';
 import 'generated/engine.dart' show TimestampedData;
 
 /// An implementation of [Source] that's based on an in-memory Dart string.
@@ skipping 22 matching lines @@
 
   String get shortName => fullName;
 
   UriKind get uriKind => throw new UnsupportedError("StringSource doesn't support "
       "uriKind.");
 
   int get hashCode => _contents.hashCode ^ fullName.hashCode;
 
   bool get isInSystemLibrary => false;
 
-  Source resolveRelative(Uri relativeUri) => throw new UnsupportedError(
+  @override
+  Uri get uri => throw new UnsupportedError(
+      "StringSource doesn't support uri.");
+
+  Uri resolveRelativeUri(Uri relativeUri) => throw new UnsupportedError(
       "StringSource doesn't support resolveRelative.");
 }