Replace the existing unittest APIs with the new runner infrastructure.

lib/src/future_matchers.dart

 // Copyright (c) 2012, 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 unittest.future_matchers;
 
 import 'dart:async';
 
 import 'package:matcher/matcher.dart' hide throws, throwsA, expect, fail;
 
-import '../unittest.dart';
+import 'expect.dart';
+import 'invoker.dart';
+import 'utils.dart';
 
 /// Matches a [Future] that completes successfully with a value.
 ///
 /// Note that this creates an asynchronous expectation. The call to `expect()`
 /// that includes this will return immediately and execution will continue.
 /// Later, when the future completes, the actual expectation will run.
 ///
 /// To test that a Future completes with an exception, you can use [throws] and
 /// [throwsA].
 final Matcher completes = const _Completes(null, '');
@@ skipping 14 matching lines @@
     new _Completes(wrapMatcher(matcher), description);
 
 class _Completes extends Matcher {
   final Matcher _matcher;
   final String _id;
 
   const _Completes(this._matcher, this._id);
 
   bool matches(item, Map matchState) {
     if (item is! Future) return false;
-    var done = expectAsync((fn) => fn(), id: _id);
+    Invoker.current.addOutstandingCallback();
 
     item.then((value) {
-      done(() {
-        if (_matcher != null) expect(value, _matcher);
-      });
+      if (_matcher != null) expect(value, _matcher);
+      Invoker.current.removeOutstandingCallback();
     }, onError: (error, trace) {
+      if (error is TestFailure) {
+        Invoker.current.handleError(error, trace);
+        return;
+      }
+
       var id = _id == '' ? '' : '${_id} ';
       var reason = 'Expected future ${id}to complete successfully, '
           'but it failed with ${error}';
       if (trace != null) {
-        var stackTrace = trace.toString();
+        var stackTrace = terseChain(trace).toString();
         stackTrace = '  ${stackTrace.replaceAll('\n', '\n  ')}';
         reason = '$reason\nStack trace:\n$stackTrace';
       }
-      done(() => fail(reason));
+      fail(reason);
     });
 
     return true;
   }
 
   Description describe(Description description) {
     if (_matcher == null) {
       description.add('completes successfully');
     } else {
       description.add('completes to a value that ').addDescriptionOf(_matcher);
     }
     return description;
   }
 }