Remove uses of Options from tools directory. Fix platform_test.

tools/line_doc_comments.dart

Index: tools/line_doc_comments.dart
diff --git a/tools/line_doc_comments.dart b/tools/line_doc_comments.dart
index 0f0fe51fb91344e1ffe8d0506a673d0a3f4c3482..855648aa423213b1fad5ef345caa25b7e006d0be 100755
--- a/tools/line_doc_comments.dart
+++ b/tools/line_doc_comments.dart
@@ -11,8 +11,7 @@ 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.');