Make more use of generated code in analysis server.

pkg/analysis_server/lib/src/services/refactoring/rename_import.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_import;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol2.dart';
-import 'package:analysis_server/src/services/correction/change.dart';
 import 'package:analysis_server/src/services/correction/status.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analysis_server/src/services/correction/source_range.dart';
 import 'package:analysis_server/src/services/refactoring/naming_conventions.dart';
 import 'package:analysis_server/src/services/refactoring/rename.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 
@@ skipping 19 matching lines @@
   }
 
   @override
   RefactoringStatus checkNewName() {
     RefactoringStatus result = super.checkNewName();
     result.addStatus(validateImportPrefixName(newName));
     return result;
   }
 
   @override
-  Future<Change> createChange() {
-    Change change = new Change(refactoringName);
+  Future<SourceChange> createChange() {
+    SourceChange change = new SourceChange(refactoringName);
     // update declaration
     {
       String file = getElementFile(element);
       PrefixElement prefix = element.prefix;
       SourceEdit edit = null;
       if (newName.isEmpty) {
         int uriEnd = element.uriEnd;
         int prefixEnd = element.prefixOffset + prefix.displayName.length;
         SourceRange range = rangeStartEnd(uriEnd, prefixEnd);
         edit = new SourceEdit.range(range, "");
@@ skipping 21 matching lines @@
           edit = createReferenceEdit(reference, newName);
         } else {
           edit = createReferenceEdit(reference, "${newName}.");
         }
         change.addEdit(reference.file, edit);
       }
       return change;
     });
   }
 }