Make more use of generated code in analysis server.

pkg/analysis_server/lib/src/services/correction/assist.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.correction.assist;
 
-import 'package:analysis_server/src/services/correction/change.dart';
+import 'package:analysis_server/src/protocol2.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
 import 'package:analysis_server/src/services/correction/assist_internal.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/source.dart';
 
 
 /**
  * Computes [Assist]s at the given location.
  *
  * Returns the computed [Assist]s, not `null`.
  */
 List<Assist> computeAssists(SearchEngine searchEngine, CompilationUnit unit,
     int offset, int length) {
   Source source = unit.element.source;
   String file = source.fullName;
   AssistProcessor processor =
       new AssistProcessor(searchEngine, source, file, unit, offset, length);
   return processor.compute();
 }
 
 
 /**
  * A description of a single proposed assist.
  */
 class Assist {
   final AssistKind kind;
-  final Change change;
+  final SourceChange change;
 
   Assist(this.kind, this.change);
 
   @override
   String toString() {
     return 'Assist(kind=$kind, change=$change)';
   }
 }
 
 
@@ skipping 82 matching lines @@
 
   final name;
   final int relevance;
   final String message;
 
   const AssistKind(this.name, this.relevance, this.message);
 
   @override
   String toString() => name;
 }