Remove generated directories with 100s of files.

client/html/generated/html/interface/CanvasElement.dart

Index: client/html/generated/html/interface/CanvasElement.dart
diff --git a/client/html/generated/html/interface/CanvasElement.dart b/client/html/generated/html/interface/CanvasElement.dart
deleted file mode 100644
index a891ae2de72df5cbb8f73e8e830a5233aa7dc055..0000000000000000000000000000000000000000
--- a/client/html/generated/html/interface/CanvasElement.dart
+++ /dev/null
@@ -1,16 +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 CanvasElement extends Element {
-
-  int height;
-
-  int width;
-
-  Object getContext(String contextId);
-
-  String toDataURL(String type);
-}