Remove need to instantiate Platform and make methods static.

tests/standalone/src/io/ProcessTestUtil.dart

Index: tests/standalone/src/io/ProcessTestUtil.dart
diff --git a/tests/standalone/src/io/ProcessTestUtil.dart b/tests/standalone/src/io/ProcessTestUtil.dart
index 459484b9672e8494c00aee603049080b99179747..0f80c3643849dade5b1dbfee7803fd89f4936030 100644
--- a/tests/standalone/src/io/ProcessTestUtil.dart
+++ b/tests/standalone/src/io/ProcessTestUtil.dart
@@ -1,16 +1,16 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// 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.
 
 String getPlatformOutDir() {
-  var os = new Platform().operatingSystem();
+  var os = Platform.operatingSystem();
   if (os == 'linux') return 'out/';
   if (os == 'macos') return 'xcodebuild/';
   return '';  // Windows.
 }
 
 String getPlatformExecutableExtension() {
-  var os = new Platform().operatingSystem();
+  var os = Platform.operatingSystem();
   if (os == 'windows') return '.exe';
   return '';  // Linux and Mac OS.
 }