cacheMisses.js

(function(w) {
  if (w != top) return

  w.addEventListener('load', function() {
    var iframe = document.createElement('iframe')
    iframe.style.display = 'none'
    iframe.src = location.href
    document.body.appendChild(iframe)
    iframe.addEventListener('load', function() {
      var outer = w.performance
      var inner = arguments[0].target.contentWindow.performance

      outer.getEntriesByType('resource').forEach(function(resource) {
        var found = inner.getEntriesByName(resource.name, 'resource')
        if (found && found.length != 0) {
          if (found[0].duration > (resource.duration / 10))
            console.info(resource, resource.name, resource.duration, found[0].duration)
        }
      })
      iframe.parentNode.removeChild(iframe)
    })
  })


})(window)