Remove uses of Options from tools directory. Fix platform_test.

tools/line_doc_comments.dart

 #!/usr/bin/env dart
 
 /// Converts block-style Doc comments in Dart code to line style.
 library line_doc_comments;
 import 'dart:io';
 
 import '../pkg/path/lib/path.dart' as path;
 
 final oneLineBlock = new RegExp(r'^(\s*)/\*\*\s?(.*)\*/\s*$');
 final startBlock = new RegExp(r'^(\s*)/\*\*(.*)$');
 final blockLine = new RegExp(r'^\s*\*\s?(.*)$');
 final endBlock = new RegExp(r'^\s*\*/\s*$');
 
-main() {
-  var args = new Options().arguments;
+main(List<String> args) {
   if (args.length != 1) {
     print('Converts "/**"-style block doc comments in a directory ');
     print('containing Dart code to "///"-style line doc comments.');
     print('');
     print('Usage: line_doc_coments.dart <dir>');
     return;
   }
 
   var dir = new Directory(args[0]);
   dir.list(recursive: true).listen(
@@ skipping 55 matching lines @@
           }
         }
       }
     }
 
     if (line != null) buffer.write('$line\n');
   }
 
   return buffer.toString();
 }