Get rid of all the library tags.

lib/src/source_registry.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.
 
-library pub.source_registry;
-
 import 'dart:collection';
 
 import 'package.dart';
 import 'source.dart';
 import 'source/unknown.dart';
 
 /// A class that keeps track of [Source]s used for getting packages.
 class SourceRegistry extends IterableBase<Source> {
   final _sources = new Map<String, Source>();
   Source _default;
@@ skipping 66 matching lines @@
   Source operator[](String name) {
     if (name == null) {
       if (defaultSource != null) return defaultSource;
       throw new StateError('No default source has been registered');
     }
 
     if (_sources.containsKey(name)) return _sources[name];
     return new UnknownSource(name);
   }
 }