More strong mode changes in analysis_server

pkg/analysis_server/lib/src/services/refactoring/rename_library.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.
 
 library services.src.refactoring.rename_library;
 
 import 'dart:async';
 
-import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/services/correction/status.dart';
 import 'package:analysis_server/src/services/refactoring/naming_conventions.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring.dart';
 import 'package:analysis_server/src/services/refactoring/rename.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analyzer/dart/element/element.dart';
 
 /**
  * A [Refactoring] for renaming [LibraryElement]s.
  */
@@ skipping 17 matching lines @@
   }
 
   @override
   RefactoringStatus checkNewName() {
     RefactoringStatus result = super.checkNewName();
     result.addStatus(validateLibraryName(newName));
     return result;
   }
 
   @override
-  Future<SourceChange> fillChange() {
+  Future fillChange() {
     addDeclarationEdit(element);
     return searchEngine.searchReferences(element).then(addReferenceEdits);
   }
 }