Remove generated directories with 100s of files.

client/html/generated/html/frog/_AudioElementFactoryProvider.dart

Index: client/html/generated/html/frog/_AudioElementFactoryProvider.dart
diff --git a/client/html/generated/html/frog/_AudioElementFactoryProvider.dart b/client/html/generated/html/frog/_AudioElementFactoryProvider.dart
deleted file mode 100644
index 789133e02a4d692d3e587ff84428f45e79f59dec..0000000000000000000000000000000000000000
--- a/client/html/generated/html/frog/_AudioElementFactoryProvider.dart
+++ /dev/null
@@ -1,10 +0,0 @@
-// 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.
-
-class _AudioElementFactoryProvider {
-  factory AudioElement([String src = null]) native '''
-      if (src == null) return new Audio();
-      return new Audio(src);
-    ''';
-}