Refactor groups to pipe them through to the runner.

lib/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 test;
 
 import 'dart:async';
 
 import 'package:path/path.dart' as p;
 
@@ skipping 23 matching lines @@
 ///
 /// This is used if a test file is run directly, rather than through the runner.
 Declarer _globalDeclarer;
 
 /// Gets the declarer for the current scope.
 ///
 /// When using the runner, this returns the [Zone]-scoped declarer that's set by
 /// [IsolateListener] or [IframeListener]. If the test file is run directly,
 /// this returns [_globalDeclarer] (and sets it up on the first call).
 Declarer get _declarer {
-  var declarer = Zone.current[#test.declarer];
+  var declarer = Declarer.current;
   if (declarer != null) return declarer;
   if (_globalDeclarer != null) return _globalDeclarer;
 
   // Since there's no Zone-scoped declarer, the test file is being run directly.
   // In order to run the tests, we set up our own Declarer via
   // [_globalDeclarer], and schedule a microtask to run the tests once they're
   // finished being defined.
   _globalDeclarer = new Declarer();
   scheduleMicrotask(() async {
     var suite = new RunnerSuite(
         // TODO(nweiz): Use a different environment if VM environment starts
         // import dart:io before cross-platform libraries exist.
         const VMEnvironment(),
-        _globalDeclarer.tests,
+        _globalDeclarer.build(),
         path: p.prettyUri(Uri.base),
         platform: TestPlatform.vm,
         os: currentOSGuess);
 
     var engine = new Engine();
     engine.suiteSink.add(suite);
     engine.suiteSink.close();
     ExpandedReporter.watch(engine,
         color: true, printPath: false, printPlatform: false);
 
@@ skipping 117 matching lines @@
 /// Each callback at the top level or in a given group will be run in the
 /// reverse of the order they were declared.
 void tearDown(callback()) => _declarer.tearDown(callback);
 
 /// Registers an exception that was caught for the current test.
 void registerException(error, [StackTrace stackTrace]) {
   // This will usually forward directly to [Invoker.current.handleError], but
   // going through the zone API allows other zones to consistently see errors.
   Zone.current.handleUncaughtError(error, stackTrace);
 }