Missed change to conform to other APIs

pkg/analyzer_plugin/lib/utilities/assist/assist_contributor_mixin.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 'package:analyzer/src/generated/java_core.dart';
 import 'package:analyzer_plugin/protocol/protocol_common.dart';
 import 'package:analyzer_plugin/protocol/protocol_generated.dart';
 import 'package:analyzer_plugin/utilities/assist/assist.dart';
 import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
 
 /**
  * A partial implementation of an [AssistContributor] that provides a utility
  * method to make it easier to add assists.
  *
  * Clients may not extend or implement this class, but are allowed to use it as
  * a mix-in when creating a subclass of [AssistContributor].
  */
 abstract class AssistContributorMixin implements AssistContributor {
   /**
    * The collector to which assists should be added.
    */
   AssistCollector get collector;
 
   /**
    * Add an assist. Use the [kind] of the assist to get the message and priority,
    * and use the change [builder] to get the edits that comprise the assist. If
    * the message has parameters, then use the list of [args] to populate the
    * message.
    */
-  void addAssistFromBuilder(ChangeBuilder builder, AssistKind kind,
-      {List<Object> args}) {
+  void addAssist(AssistKind kind, ChangeBuilder builder, {List<Object> args}) {
     SourceChange change = builder.sourceChange;
     if (change.edits.isEmpty) {
       return;
     }
     change.message = formatList(kind.message, args);
     collector.addAssist(
         new PrioritizedSourceChange(kind.priority, builder.sourceChange));
   }
 }