Convert /** comments to /// in pub.

utils/pub/git.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.
 
-/**
- * Helper functionality for invoking Git.
- */
+/// Helper functionality for invoking Git.
 library git;
 
 import 'io.dart';
 import 'log.dart' as log;
 import 'utils.dart';
 
 /// Tests whether or not the git command-line app is available for use.
 Future<bool> get isInstalled {
   if (_isGitInstalledCache != null) {
     // TODO(rnystrom): The sleep is to pump the message queue. Can use
@@ skipping 59 matching lines @@
                        regex.hasMatch(results.stdout[0]));
   });
 
   future.handleException((err) {
     // If the process failed, they probably don't have it.
     completer.complete(false);
     return true;
   });
 
   return completer.future;
-}
+}