Get rid of #source in pub.

utils/pub/pubspec.dart

Index: utils/pub/pubspec.dart
diff --git a/utils/pub/pubspec.dart b/utils/pub/pubspec.dart
index d38e75f017753af393849e80a01fac3c4ab06219..dfd8dfde41bd0feaece2b45cee57a730fac18bd3 100644
--- a/utils/pub/pubspec.dart
+++ b/utils/pub/pubspec.dart
@@ -2,11 +2,12 @@
 // 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_pubspec');
+#library('pubspec');
 
 #import('io.dart');
-#import('pub.dart');
+#import('package.dart');
 #import('source.dart');
+#import('source_registry.dart');
 #import('utils.dart');
 #import('version.dart');
 #import('yaml/yaml.dart');