Add test- and group-level support for skipping tests.

lib/src/runner/loader.dart

 // Copyright (c) 2015, 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.runner.loader;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:isolate';
 
 import 'package:analyzer/analyzer.dart';
 import 'package:path/path.dart' as p;
 
+import '../backend/invoker.dart';
 import '../backend/metadata.dart';
 import '../backend/suite.dart';
 import '../backend/test_platform.dart';
 import '../util/dart.dart';
 import '../util/io.dart';
 import '../util/isolate_wrapper.dart';
 import '../util/remote_exception.dart';
 import '../utils.dart';
 import 'browser/server.dart';
 import 'load_exception.dart';
@@ skipping 98 matching lines @@
       return new Stream.fromFuture(
           new Future.error(new LoadException(path, error), stackTrace));
     }
 
     var controller = new StreamController();
     Future.forEach(_platforms, (platform) {
       if (!metadata.testOn.evaluate(platform, os: currentOS)) {
         return new Future.value();
       }
 
+      // Don't load a skipped suite.
+      if (metadata.skip) {
+        return new Future.value(new Suite([
+          new LocalTest(path, metadata, () {})
+        ], path: path, platform: platform.name, metadata: metadata));
+      }
+
       return new Future.sync(() {
         if (_pubServeUrl != null && !p.isWithin('test', path)) {
           throw new LoadException(path,
               'When using "pub serve", all test files must be in test/.');
         }
 
         if (platform == TestPlatform.vm) return _loadVmFile(path, metadata);
         assert(platform.isBrowser);
         return _loadBrowserFile(path, platform, metadata);
       }).then((suite) {
@@ skipping 88 matching lines @@
   Future close() {
     for (var isolate in _isolates) {
       isolate.kill();
     }
     _isolates.clear();
 
     if (_browserServerCompleter == null) return new Future.value();
     return _browserServer.then((browserServer) => browserServer.close());
   }
 }