Changed final to const in apidoc.

utils/apidoc/scripts/list_files.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Traverses apidoc and dartdoc and lists all possible input files that are
  * used when building API documentation. Used by gyp to determine when apidocs
  * need to be regenerated (see `apidoc.gyp`).
  */
 #library('list_files');
 
 #import('dart:io');
 
-final allowedExtensions = const [
+const allowedExtensions = const [
   '.css', '.dart', '.ico', '.js', '.json', '.png', '.sh', '.txt'
 ];
 
 void main() {
   final scriptDir = new File(new Options().script).directorySync().path;
   final dartDir = '$scriptDir/../../../';
   listFiles('$dartDir/utils/apidoc');
   listFiles('$dartDir/pkg/dartdoc');
 }
 
 void listFiles(String dirPath) {
   final dir = new Directory(dirPath);
 
   dir.onFile = (path) {
     if (allowedExtensions.indexOf(extension(path)) != -1) {
       print(path);
     }
   };
 
   dir.list(recursive: true);
 }
 
 String extension(String path) {
   int lastDot = path.lastIndexOf('.');
   if (lastDot == -1) return '';
 
   return path.substring(lastDot);
 }