Properly handle synchronous errors in Chain.capture.

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';
 import 'package:unittest/unittest.dart';
 
 import 'utils.dart';
 
 void main() {
   group('capture() with onError catches exceptions', () {
+    test('thrown synchronously', () {
+      return captureFuture(() => throw 'error')
+          .then((chain) {
+        expect(chain.traces, hasLength(1));
+        expect(chain.traces.single.frames.first,
+            frameMember(startsWith('main')));
+      });
+    });
+
     test('thrown in a microtask', () {
       return captureFuture(() => inMicrotask(() => throw 'error'))
           .then((chain) {
         // Since there was only one asynchronous operation, there should be only
         // two traces in the chain.
         expect(chain.traces, hasLength(2));
 
         // The first frame of the first trace should be the line on which the
         // actual error was thrown.
         expect(chain.traces[0].frames.first, frameMember(startsWith('main')));
@@ skipping 695 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;
 }