Roll forward revision 37912.

pkg/barback/lib/src/utils.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.
 
 library barback.utils;
 
 import 'dart:async';
 import 'dart:typed_data';
 
 import 'package:stack_trace/stack_trace.dart';
@@ skipping 318 matching lines @@
 /// A regular expression to match the exception prefix that some exceptions'
 /// [Object.toString] values contain.
 final _exceptionPrefix = new RegExp(r'^([A-Z][a-zA-Z]*)?(Exception|Error): ');
 
 /// Get a string description of an exception.
 ///
 /// Many exceptions include the exception class name at the beginning of their
 /// [toString], so we remove that if it exists.
 String getErrorMessage(error) =>
   error.toString().replaceFirst(_exceptionPrefix, '');
+
+/// Returns a human-friendly representation of [duration].
+String niceDuration(Duration duration) {
+  var result = duration.inMinutes > 0 ? "${duration.inMinutes}:" : "";
+
+  var s = duration.inSeconds % 59;
+  var ms = (duration.inMilliseconds % 1000) ~/ 100;
+  return result + "$s.${ms}s";
+}