public static Standard::filterXss($html, FilterFormatInterface $format, FilterFormatInterface $original_format = NULL)
Filters HTML to prevent XSS attacks when a user edits it in a text editor.
Should filter as minimally as possible, only to remove XSS attack vectors.
Is only called when:
loading a non-XSS-safe text editor for a $format that contains a filter preventing XSS attacks (a FilterInterface::TYPE_HTML_RESTRICTOR filter): if the output is safe, it should also be safe to edit. loading a