Minor code clean-up

pkg/analyzer/lib/src/generated/scanner.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 engine.scanner;
 
 import 'dart:collection';
@@ skipping 106 matching lines @@
   }
 
   @override
   int get offset => _charOffset;
 
   @override
   String getString(int start, int endDelta) => _sequence.substring(start, _charOffset + 1 + endDelta).toString();
 
   @override
   int peek() {
-    if (_charOffset + 1 >= _sequence.length) {
+    if (_charOffset + 1 >= _stringLength) {
       return -1;
     }
     return _sequence.codeUnitAt(_charOffset + 1);
   }
 
   @override
   void set offset(int offset) {
     _charOffset = offset;
   }
 }
@@ skipping 2545 matching lines @@
    * @param precedingComment the first comment in the list of comments that precede this token
    */
   TokenWithComment(TokenType type, int offset, this._precedingComment) : super(type, offset);
 
   @override
   Token copy() => new TokenWithComment(type, offset, _precedingComment);
 
   @override
   Token get precedingComments => _precedingComment;
 }