Update charted to 0.4.8 and roll

packages/source_span/test/utils_test.dart

 // Copyright (c) 2013, 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.
 
 import 'package:test/test.dart';
 import 'package:source_span/src/utils.dart';
 
 main() {
   group('find line start', () {
     test('skip entries in wrong column', () {
@@ skipping 27 matching lines @@
       expect(index, 0);
     });
 
     test('not found', () {
       var context = '0\n2\n45\n';
       var index = findLineStart(context, '0', 1);
       expect(index, isNull);
     });
   });
 }
-
-_linearSearch(list, predicate) {
-  if (list.length == 0) return -1;
-  for (int i = 0; i < list.length; i++) {
-    if (predicate(list[i])) return i;
-  }
-  return list.length;
-}