Add tests for stack chains in the browser.

lib/src/chain.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 stack_trace.chain;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:math' as math;
 
@@ skipping 50 matching lines @@
   /// error. Note that if [callback] produces multiple unhandled errors,
   /// [onError] may be called more than once. If [onError] isn't passed, the
   /// parent Zone's `unhandledErrorHandler` will be called with the error and
   /// its chain.
   ///
   /// Note that even if [onError] isn't passed, this zone will still be an error
   /// zone. This means that any errors that would cross the zone boundary are
   /// considered unhandled.
   ///
   /// If [callback] returns a value, it will be returned by [capture] as well.
-  ///
-  /// Currently, capturing stack chains doesn't work when using dart2js due to
-  /// issues [15171] and [15105]. Stack chains reported on dart2js will contain
-  /// only one trace.
-  ///
-  /// [15171]: https://code.google.com/p/dart/issues/detail?id=15171
-  /// [15105]: https://code.google.com/p/dart/issues/detail?id=15105
   static capture(callback(), {ChainHandler onError}) {
     var spec = new StackZoneSpecification(onError);
     return runZoned(() {
       try {
         return callback();
       } catch (error, stackTrace) {
         // TODO(nweiz): Don't special-case this when issue 19566 is fixed.
         return Zone.current.handleUncaughtError(error, stackTrace);
       }
     }, zoneSpecification: spec.toSpec(), zoneValues: {
@@ skipping 106 matching lines @@
 
     // Don't call out to [Trace.toString] here because that doesn't ensure that
     // padding is consistent across all traces.
     return traces.map((trace) {
       return trace.frames.map((frame) {
         return '${padRight(frame.location, longest)}  ${frame.member}\n';
       }).join();
     }).join(_gap);
   }
 }