Support an @OnPlatform annotation.

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';
 
@@ skipping 94 matching lines @@
       }
 
       return loadFile(entry.path);
     }));
   }
 
   /// Loads a test suite from the file at [path].
   ///
   /// This will emit a [LoadException] if the file fails to load.
   Stream<Suite> loadFile(String path) {
-    var metadata;
+    var suiteMetadata;
     try {
-      metadata = parseMetadata(path);
+      suiteMetadata = parseMetadata(path);
     } on AnalyzerErrorGroup catch (_) {
       // Ignore the analyzer's error, since its formatting is much worse than
       // the VM's or dart2js's.
-      metadata = new Metadata();
+      suiteMetadata = new Metadata();
     } on FormatException catch (error, stackTrace) {
       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)) {
+      if (!suiteMetadata.testOn.evaluate(platform, os: currentOS)) {
         return null;
       }
 
+      var metadata = suiteMetadata.forPlatform(platform, os: currentOS);
+
       // Don't load a skipped suite.
       if (metadata.skip) {
         controller.add(new Suite([
           new LocalTest(path, metadata, () {})
         ], path: path, platform: platform.name, metadata: metadata));
         return null;
       }
 
       return new Future.sync(() {
         if (_pubServeUrl != null && !p.isWithin('test', path)) {
@@ skipping 94 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());
   }
 }