Avoid timeouts in stack_trace's chain_test.

pkg/stack_trace/test/chain_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.
 
 library chain_test;
 
 import 'dart:async';
 
 import 'package:path/path.dart' as p;
 import 'package:stack_trace/stack_trace.dart';
@@ skipping 74 matching lines @@
     });
 
     test('multiple times', () {
       var completer = new Completer();
       var first = true;
 
       Chain.capture(() {
         inMicrotask(() => throw 'first error');
         inPeriodicTimer(() => throw 'second error');
       }, onError: (error, chain) {
-        if (first) {
-          expect(error, equals('first error'));
-          expect(chain.traces[1].frames,
-              contains(frameMember(startsWith('inMicrotask'))));
-          first = false;
-        } else {
-          expect(error, equals('second error'));
-          expect(chain.traces[1].frames,
-              contains(frameMember(startsWith('inPeriodicTimer'))));
-          completer.complete();
+        try {
+          if (first) {
+            expect(error, equals('first error'));
+            expect(chain.traces[1].frames,
+                contains(frameMember(startsWith('inMicrotask'))));
+            first = false;
+          } else {
+            expect(error, equals('second error'));
+            expect(chain.traces[1].frames,
+                contains(frameMember(startsWith('inPeriodicTimer'))));
+            completer.complete();
+          }
+        } catch (error, stackTrace) {
+          completer.completeError(error, stackTrace);
         }
       });
 
       return completer.future;
     });
 
     test('and relays them to the parent zone', () {
       var completer = new Completer();
 
       runZoned(() {
         Chain.capture(() {
           inMicrotask(() => throw 'error');
         }, onError: (error, chain) {
           expect(error, equals('error'));
           expect(chain.traces[1].frames,
               contains(frameMember(startsWith('inMicrotask'))));
           throw error;
         });
       }, onError: (error, chain) {
-        expect(error, equals('error'));
-        expect(chain, new isInstanceOf<Chain>());
-        expect(chain.traces[1].frames,
-            contains(frameMember(startsWith('inMicrotask'))));
-        completer.complete();
+        try {
+          expect(error, equals('error'));
+          expect(chain, new isInstanceOf<Chain>());
+          expect(chain.traces[1].frames,
+              contains(frameMember(startsWith('inMicrotask'))));
+          completer.complete();
+        } catch (error, stackTrace) {
+          completer.completeError(error, stackTrace);
+        }
       });
 
       return completer.future;
     });
   });
 
   test('capture() without onError passes exceptions to parent zone', () {
     var completer = new Completer();
 
     runZoned(() {
       Chain.capture(() => inMicrotask(() => throw 'error'));
     }, onError: (error, chain) {
-      expect(error, equals('error'));
-      expect(chain, new isInstanceOf<Chain>());
-      expect(chain.traces[1].frames,
-          contains(frameMember(startsWith('inMicrotask'))));
-      completer.complete();
+      try {
+        expect(error, equals('error'));
+        expect(chain, new isInstanceOf<Chain>());
+        expect(chain.traces[1].frames,
+            contains(frameMember(startsWith('inMicrotask'))));
+        completer.complete();
+      } catch (error, stackTrace) {
+        completer.completeError(error, stackTrace);
+      }
     });
 
     return completer.future;
   });
 
   group('current() within capture()', () {
     test('called in a microtask', () {
       var completer = new Completer();
       Chain.capture(() {
         inMicrotask(() => completer.complete(new Chain.current()));
@@ skipping 554 matching lines @@
 ///
 /// [callback] is expected to throw the string `"error"`.
 Future<Chain> captureFuture(callback()) {
   var completer = new Completer<Chain>();
   Chain.capture(callback, onError: (error, chain) {
     expect(error, equals('error'));
     completer.complete(chain);
   });
   return completer.future;
 }