Make server use the common protocol classes

pkg/analysis_server/lib/plugin/edit/assist/assist_core.dart

Index: pkg/analysis_server/lib/plugin/edit/assist/assist_core.dart
diff --git a/pkg/analysis_server/lib/plugin/edit/assist/assist_core.dart b/pkg/analysis_server/lib/plugin/edit/assist/assist_core.dart
index 704a68de36485a8f71b99023185838289b889df3..31506b9a9d8f00f774672acea442549947054a74 100644
--- a/pkg/analysis_server/lib/plugin/edit/assist/assist_core.dart
+++ b/pkg/analysis_server/lib/plugin/edit/assist/assist_core.dart
@@ -2,14 +2,12 @@
 // 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 analysis_server.plugin.edit.assist.assist_core;
-
 import 'dart:async';
 
-import 'package:analysis_server/protocol/protocol_generated.dart'
-    show SourceChange;
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer_plugin/protocol/protocol_common.dart'
+    show SourceChange;
 
 /**
  * A description of a single proposed assist.