Remove need to instantiate Platform and make methods static.

utils/compiler/build_helper.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.
 
 #import('dart:io');
 #import('dart:uri');
 
 main() {
   List<String> arguments = new Options().arguments;
   Uri uri = new Uri(scheme: 'file', path: '${arguments[0]}/');
@@ skipping 13 matching lines @@
 writeScript(Uri uri, List<String> chunks) {
   var f = new File(uri.path);
   var stream = f.openSync(FileMode.WRITE);
   for (String chunk in chunks) {
     stream.writeStringSync(chunk);
   }
   stream.closeSync();
 
   // TODO(ahe): Also make a .bat file for Windows.
 
-  if (new Platform().operatingSystem() != 'windows') {
+  if (Platform.operatingSystem() != 'windows') {
     onExit(int exitCode, String stdout, String stderr) {
       if (exitCode != 0) {
         print(stdout);
         print(stderr);
         exit(exitCode);
       }
     }
     new Process.run('/bin/chmod', ['+x', uri.path], null, onExit);
   }
 }
@@ skipping 30 matching lines @@
       }
     }
   }
 }
 
 void main() {
   new Helper().run();
 }
 """;
 }