Remove need to instantiate Platform and make methods static.

tests/standalone/src/io/DirectoryErrorTest.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.
 //
 // Dart test program for testing error handling in directory I/O.
 
 #import("dart:io");
 #import("dart:isolate");
 
 Directory tempDir() {
   var d = new Directory('');
   d.createTempSync();
   return d;
 }
 
 
 bool checkCreateInNonExistentFileException(e) {
   Expect.isTrue(e is DirectoryIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf("Creation failed") != -1);
-  Platform platform = new Platform();
-  if (platform.operatingSystem() == "linux") {
+  if (Platform.operatingSystem() == "linux") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
-  } else if (platform.operatingSystem() == "macos") {
+  } else if (Platform.operatingSystem() == "macos") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
-  } else if (platform.operatingSystem() == "windows") {
+  } else if (Platform.operatingSystem() == "windows") {
     Expect.isTrue(
         e.toString().indexOf(
             "The system cannot find the path specified") != -1);
     Expect.equals(3, e.osError.errorCode);
   }
 
   return true;
 }
 
 
 void testCreateInNonExistent(Directory temp, Function done) {
   Directory inNonExistent = new Directory("${temp.path}/nonExistent/xxx");
   Expect.throws(() => inNonExistent.createSync(),
                 (e) => checkCreateInNonExistentFileException(e));
 
   inNonExistent.create(() => Expect.fail("Unreachable code"));
   inNonExistent.onError = (e) {
     checkCreateInNonExistentFileException(e);
     done();
   };
 }
 
 
 bool checkCreateTempInNonExistentFileException(e) {
   Expect.isTrue(e is DirectoryIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf(
       "Creation of temporary directory failed") != -1);
-  Platform platform = new Platform();
-  if (platform.operatingSystem() == "linux") {
+  if (Platform.operatingSystem() == "linux") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
-  } else if (platform.operatingSystem() == "macos") {
+  } else if (Platform.operatingSystem() == "macos") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
-  } else if (platform.operatingSystem() == "windows") {
+  } else if (Platform.operatingSystem() == "windows") {
     Expect.isTrue(
         e.toString().indexOf(
             "The system cannot find the path specified") != -1);
     Expect.equals(3, e.osError.errorCode);
   }
 
   return true;
 }
 
 
 void testCreateTempInNonExistent(Directory temp, Function done) {
   Directory nonExistent = new Directory("${temp.path}/nonExistent/xxx");
   Expect.throws(() => nonExistent.createTempSync(),
                 (e) => checkCreateTempInNonExistentFileException(e));
 
   nonExistent.createTemp(() => Expect.fail("Unreachable code"));
   nonExistent.onError = (e) {
     checkCreateTempInNonExistentFileException(e);
     done();
   };
 }
 
 
 bool checkDeleteNonExistentFileException(e) {
   Expect.isTrue(e is DirectoryIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf("Deletion failed") != -1);
-  Platform platform = new Platform();
-  if (platform.operatingSystem() == "linux") {
+  if (Platform.operatingSystem() == "linux") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
-  } else if (platform.operatingSystem() == "macos") {
+  } else if (Platform.operatingSystem() == "macos") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
-  } else if (platform.operatingSystem() == "windows") {
+  } else if (Platform.operatingSystem() == "windows") {
     Expect.isTrue(
         e.toString().indexOf(
             "The system cannot find the file specified") != -1);
   }
   // File not not found has error code 2 on all supported platforms.
   Expect.equals(2, e.osError.errorCode);
 
   return true;
 }
 
 
 void testDeleteNonExistent(Directory temp, Function done) {
   Directory nonExistent = new Directory("${temp.path}/nonExistent");
   Expect.throws(() => nonExistent.deleteSync(),
                 (e) => checkDeleteNonExistentFileException(e));
 
   nonExistent.delete(() => Expect.fail("Unreachable code"));
   nonExistent.onError = (e) {
     checkDeleteNonExistentFileException(e);
     done();
   };
 }
 
 
 bool checkDeleteRecursivelyNonExistentFileException(e) {
   Expect.isTrue(e is DirectoryIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf("Deletion failed") != -1);
-  Platform platform = new Platform();
-  if (platform.operatingSystem() == "linux") {
+  if (Platform.operatingSystem() == "linux") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
-  } else if (platform.operatingSystem() == "macos") {
+  } else if (Platform.operatingSystem() == "macos") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
-  } else if (platform.operatingSystem() == "windows") {
+  } else if (Platform.operatingSystem() == "windows") {
     Expect.isTrue(
         e.toString().indexOf(
             "The system cannot find the path specified") != -1);
     Expect.equals(3, e.osError.errorCode);
   }
 
   return true;
 }
 
 
 void testDeleteRecursivelyNonExistent(Directory temp, Function done) {
   Directory nonExistent = new Directory("${temp.path}/nonExistent");
   Expect.throws(() => nonExistent.deleteRecursivelySync(),
                 (e) => checkDeleteRecursivelyNonExistentFileException(e));
 
   nonExistent.deleteRecursively(() => Expect.fail("Unreachable code"));
   nonExistent.onError = (e) {
     checkDeleteRecursivelyNonExistentFileException(e);
     done();
   };
 }
 
 
 bool checkListNonExistentFileException(e) {
   Expect.isTrue(e is DirectoryIOException);
   Expect.isTrue(e.osError != null);
   Expect.isTrue(e.toString().indexOf("Directory listing failed") != -1);
-  Platform platform = new Platform();
-  if (platform.operatingSystem() == "linux") {
+  if (Platform.operatingSystem() == "linux") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
-  } else if (platform.operatingSystem() == "macos") {
+  } else if (Platform.operatingSystem() == "macos") {
     Expect.isTrue(e.toString().indexOf("No such file or directory") != -1);
     Expect.equals(2, e.osError.errorCode);
-  } else if (platform.operatingSystem() == "windows") {
+  } else if (Platform.operatingSystem() == "windows") {
     Expect.isTrue(
         e.toString().indexOf(
             "The system cannot find the path specified") != -1);
     Expect.equals(3, e.osError.errorCode);
   }
 
   return true;
 }
 
 
@@ skipping 24 matching lines @@
 }
 
 
 main() {
   runTest(testCreateInNonExistent);
   runTest(testCreateTempInNonExistent);
   runTest(testDeleteNonExistent);
   runTest(testDeleteRecursivelyNonExistent);
   runTest(testListNonExistent);
 }