ViewCookie is not found on HTMLDataObject due to
strange implementation of createCookie method.

Node.Cookie createCookie (Class klass) {
...
if (klass == ViewSupport.class) {
            return new ViewSupport(getPrimaryEntry());
        }
...
}

where ViewSupport implements ViewCookie, but the
if condition above
is not satisfied for ViewCookie.

Condition should like:
if (ViewCookie.isAssignableFrom (klass)) {
   return new ViewSupport(getPrimaryEntry());
}

The same holds for HtmlEditorSupport case in the
same method.