Update charted to 0.4.8 and roll

packages/stack_trace/lib/src/vm_trace.dart

Index: packages/stack_trace/lib/src/vm_trace.dart
diff --git a/packages/stack_trace/lib/src/vm_trace.dart b/packages/stack_trace/lib/src/vm_trace.dart
index 79911602ac7b59abadfc31d8315a8a17eb93c186..7086df70022710ebe4b7cf76a8a1d8ce4be3aabc 100644
--- a/packages/stack_trace/lib/src/vm_trace.dart
+++ b/packages/stack_trace/lib/src/vm_trace.dart
@@ -2,10 +2,7 @@
 // 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 vm_trace;
-
 import 'frame.dart';
-import 'utils.dart';
 
 /// An implementation of [StackTrace] that emulates the behavior of the VM's
 /// implementation.
@@ -21,7 +18,7 @@ class VMTrace implements StackTrace {
   String toString() {
     var i = 1;
     return frames.map((frame) {
-      var number = padRight("#${i++}", 8);
+      var number = "#${i++}".padRight(8);
       var member = frame.member
           .replaceAllMapped(new RegExp(r"[^.]+\.<async>"),
               (match) => "${match[1]}.<${match[1]}_async_body>")