Split File into File and RandomAccessFile.

utils/markdown/markdown.dart

Index: utils/markdown/markdown.dart
diff --git a/utils/markdown/markdown.dart b/utils/markdown/markdown.dart
index 8d818baf2c6a2f1e43767057d4434ca2b91b2cbc..bf1d691b2fe09239a59d31ab6d052d047736f474 100644
--- a/utils/markdown/markdown.dart
+++ b/utils/markdown/markdown.dart
@@ -30,8 +30,7 @@ main() {
 }
 
 String readFile(String path) {
-  final file = new File(path);
-  file.openSync();
+  final file = (new File(path)).openSync();
   final length = file.lengthSync();
   final buffer = new List<int>(length);
   final bytes = file.readListSync(buffer, 0, length);