>>>
return options.releaseMode &&

  // TODO(sigmund): remove this exclusion once we have dev_transformers
  // (dartbug.com/14187)
  !id.path.startsWith('lib/') &&

  // may filter non-entry HTML files and internal artifacts
  (id.extension == '.html' || id.extension == _DATA_EXTENSION) &&

  // keep any entry points
  !options.isHtmlEntryPoint(id);
<<<
return options.releaseMode &&
    // TODO(sigmund): remove this exclusion once we have dev_transformers
    // (dartbug.com/14187)
    !id.path.startsWith('lib/') &&
    // may filter non-entry HTML files and internal artifacts
    (id.extension == '.html' || id.extension == _DATA_EXTENSION) &&
    // keep any entry points
    !options.isHtmlEntryPoint(id);