Remove generated directories with 100s of files.

client/html/generated/html/dartium/HTMLOptionsCollection.dart

Index: client/html/generated/html/dartium/HTMLOptionsCollection.dart
diff --git a/client/html/generated/html/dartium/HTMLOptionsCollection.dart b/client/html/generated/html/dartium/HTMLOptionsCollection.dart
deleted file mode 100644
index 3d8d0ffae12b52afca005034f7b35390090da8b8..0000000000000000000000000000000000000000
--- a/client/html/generated/html/dartium/HTMLOptionsCollection.dart
+++ /dev/null
@@ -1,17 +0,0 @@
-
-class _HTMLOptionsCollectionImpl extends _HTMLCollectionImpl implements HTMLOptionsCollection {
-  _HTMLOptionsCollectionImpl._wrap(ptr) : super._wrap(ptr);
-
-  int get length() => _wrap(_ptr.length);
-
-  void set length(int value) { _ptr.length = _unwrap(value); }
-
-  int get selectedIndex() => _wrap(_ptr.selectedIndex);
-
-  void set selectedIndex(int value) { _ptr.selectedIndex = _unwrap(value); }
-
-  void remove(int index) {
-    _ptr.remove(_unwrap(index));
-    return;
-  }
-}