Version fixed for Windows.

tools/testing/dart/version.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.
 
 /**
  * This file contains functionality for getting dart version numbers using
  * our standard version construction method. Systems that does not include this
  * file should emulate the structure for revision numbers that we have here.
  *
  * The version number of a dart build is constructed as follows:
@@ skipping 94 matching lines @@
             return;
           });
         }
       };
     });
     return c.future;
   }
 
   String getExecutableSuffix() {
     if (Platform.operatingSystem == 'windows') {
-      return '.exe';
+      return '.bat';
     }
     return '';
   }
 
   Future<int> getRevision() {
     if (repositoryType == RepositoryType.UNKNOWN) {
       return new Future.immediate(0);
     }
     var isSvn = repositoryType == RepositoryType.SVN;
     var command = isSvn ? "svn" : "git";
@@ skipping 10 matching lines @@
         String revisionString = result.stdout.split("\n")[8].substring(18);
         return int.parse(revisionString);
       } catch (e) {
         return 0;
       }
     });
   }
 
   String getUserName() {
     // TODO(ricow): Don't add this on the buildbot.
-    if (!Platform.environment.containsKey("USER")) return "";
-    return Platform.environment["USER"];
+    var key = "USER";
+    if (Platform.operatingSystem == 'windows') {
+      key = "USERNAME";
+    }
+    if (!Platform.environment.containsKey(key)) return "";
+    return Platform.environment[key];
   }
 
   RepositoryType get repositoryType {
     if (new Directory(".svn").existsSync()) return RepositoryType.SVN;
     if (new Directory(".git").existsSync()) return RepositoryType.GIT;
     return RepositoryType.UNKNOWN;
   }
 }
 
 class RepositoryType {
   static final RepositoryType SVN = const RepositoryType("SVN");
   static final RepositoryType GIT = const RepositoryType("GIT");
   static final RepositoryType UNKNOWN = const RepositoryType("UNKNOWN");
 
   const RepositoryType(String this.name);
 
   static RepositoryType guessType() {
     if (new Directory(".svn").existsSync()) return RepositoryType.SVN;
     if (new Directory(".git").existsSync()) return RepositoryType.GIT;
     return RepositoryType.UNKNOWN;
   }
 
   String toString() => name;
 
   final String name;
 }