Remove generated directories with 100s of files.

client/html/generated/html/interface/OESStandardDerivatives.dart

Index: client/html/generated/html/interface/OESStandardDerivatives.dart
diff --git a/client/html/generated/html/interface/OESStandardDerivatives.dart b/client/html/generated/html/interface/OESStandardDerivatives.dart
deleted file mode 100644
index f109c265e3155030fe41d99f5e6d2486288576e2..0000000000000000000000000000000000000000
--- a/client/html/generated/html/interface/OESStandardDerivatives.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.
-
-// WARNING: Do not edit - generated code.
-
-interface OESStandardDerivatives {
-
-  static final int FRAGMENT_SHADER_DERIVATIVE_HINT_OES = 0x8B8B;
-}