Implement more fixes.

pkg/analysis_services/lib/src/correction/source_buffer.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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library services.src.correction.source_buffer;
 
 import 'package:analysis_services/correction/change.dart';
@@ skipping 17 matching lines @@
 
   void addProposal(String proposal) {
     // TODO(scheglov) implement
 //    _currentPositionGroup.addProposal();
   }
 
   void addProposals(List<String> proposals) {
     proposals.forEach((proposal) => addProposal(proposal));
   }
 
+  int get length => _buffer.length;
+
   /**
    * Appends [s] to the buffer.
    */
   SourceBuilder append(String s) {
     _buffer.write(s);
     return this;
   }
 
   /**
    * Ends position started using [startPosition].
@@ skipping 28 matching lines @@
   /**
    * Adds position location [SourceRange] using current fields.
    */
   void _addPosition() {
     int start = offset + _currentPositionStart;
     int end = offset + _buffer.length;
     Position position = new Position(file, start, end - start);
     _currentLinkedPositionGroup.add(position);
   }
 }