Deprecate the ChainHandler typedef.

lib/src/stack_zone_specification.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.stack_zone_specification;
 
 import 'dart:async';
 
 import 'trace.dart';
 import 'chain.dart';
 
+/// A function that handles errors in the zone wrapped by [Chain.capture].
+typedef void _ChainHandler(error, Chain chain);
+
 /// A class encapsulating the zone specification for a [Chain.capture] zone.
 ///
 /// Until they're materialized and exposed to the user, stack chains are tracked
 /// as linked lists of [Trace]s using the [_Node] class. These nodes are stored
 /// in three distinct ways:
 ///
 /// * When a callback is registered, a node is created and stored as a captured
 ///   local variable until the callback is run.
 ///
 /// * When a callback is run, its captured node is set as the [_currentNode] so
@@ skipping 14 matching lines @@
   /// used with expandos.
   ///
   /// The chain associated with a given stack trace doesn't contain a node for
   /// that stack trace.
   final _chains = new Expando<_Node>("stack chains");
 
   /// The error handler for the zone.
   ///
   /// If this is null, that indicates that any unhandled errors should be passed
   /// to the parent zone.
-  final ChainHandler _onError;
+  final _ChainHandler _onError;
 
   /// The most recent node of the current stack chain.
   _Node _currentNode;
 
   StackZoneSpecification([this._onError]);
 
   /// Converts [this] to a real [ZoneSpecification].
   ZoneSpecification toSpec() {
     return new ZoneSpecification(
         handleUncaughtError: handleUncaughtError,
@@ skipping 170 matching lines @@
   Chain toChain() {
     var nodes = <Trace>[];
     var node = this;
     while (node != null) {
       nodes.add(node.trace);
       node = node.previous;
     }
     return new Chain(nodes);
   }
 }