Add SourceFileEdit.time field.

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/protocol.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/correction/util.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';
 
 
 /**
  * A [Refactoring] for renaming [ImportElement]s.
@@ skipping 41 matching lines @@
           SourceRange range = rangeStartLength(element.uriEnd, 0);
           edit = new SourceEdit.range(range, " as ${newName}");
         } else {
           int offset = element.prefixOffset;
           int length = prefix.displayName.length;
           SourceRange range = rangeStartLength(offset, length);
           edit = new SourceEdit.range(range, newName);
         }
       }
       if (edit != null) {
-        change.addEdit(file, edit);
+        addElementSourceChange(change, element, edit);
       }
     }
     // update references
     return searchEngine.searchReferences(element).then((refMatches) {
       List<SourceReference> references = getSourceReferences(refMatches);
       for (SourceReference reference in references) {
         SourceEdit edit;
         if (newName.isEmpty) {
           edit = createReferenceEdit(reference, newName);
         } else {
           edit = createReferenceEdit(reference, "${newName}.");
         }
-        change.addEdit(reference.file, edit);
+        addElementSourceChange(change, reference.element, edit);
       }
       return change;
     });
   }
 }