def all_stylesheet_paths
      all_paths = []
      all_paths += @stylesheets
      all_paths += @content_scripts.map { |cs| cs.stylesheets }.compact
      all_paths.flatten.uniq
    end
def all_stylesheet_paths
      all_paths = []
      all_paths += @stylesheets
      all_paths += @content_scripts.map { |cs| cs.stylesheets }.compact
      all_paths.flatten.uniq
    end
Return all the stylesheet paths in the spec, included those nested
 inside other objects