RemoveNonEditingHtmlElements.cs

 public class RemoveNonEditingHtmlElements : HttpRequestProcessor
    {
        public override void Process(HttpRequestArgs args)
        {
            if (args.HttpContext.Response.HeadersWritten ||
                Context.Site == null ||
                Context.Site.Name == "shell" ||
                Context.Item == null)
            {
                return;
            }

            var ctx = args.HttpContext.Response;

            if (ctx.Filter == null)
            {
                return;
            }

            var filter = ctx.Filter;

            var extenderResponseFilter = new RemoveHtmlElementResponseFilter(filter);
            extenderResponseFilter.Flush();
            ctx.Filter = extenderResponseFilter;
        }
    }