Remove timeStamp from the ChangeBuilder API

pkg/analyzer_plugin/lib/utilities/change_builder/change_builder_core.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:async';
 
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:analyzer_plugin/src/utilities/change_builder/change_builder_core.dart';
 
@@ skipping 10 matching lines @@
 
   /**
    * Return the source change that was built. The source change will not be
    * complete until all of the futures returned by [addFileEdit] have completed.
    */
   SourceChange get sourceChange;
 
   /**
    * Use the [buildFileEdit] function to create a collection of edits to the
    * file with the given [path]. The edits will be added to the source change
-   * that is being built. The [timeStamp] is the time at which the file was last
-   * modified and is used by clients to ensure that it is safe to apply the
-   * edits.
+   * that is being built.
    */
   Future<Null> addFileEdit(
-      String path, int timeStamp, void buildFileEdit(FileEditBuilder builder));
+      String path, void buildFileEdit(FileEditBuilder builder));
 
   /**
    * Set the selection for the change being built to the given [position].
    */
   void setSelection(Position position);
 }
 
 /**
  * A builder used to build a [SourceEdit] as part of a [SourceFileEdit].
  *
@@ skipping 129 matching lines @@
    * Add the given [string] to the content of the current edit.
    */
   void write(String string);
 
   /**
    * Add the given [string] to the content of the current edit and then add an
    * end-of-line marker.
    */
   void writeln([String string]);
 }