Better privacy for youtube videos

Thanks for #35 :-)

Just FYI if you switch to the nocookie domain cookies get still loaded, external fonts.
Even if you link the hir-es image from youtube directly cookies are set.
The only solutions seems to be to load and use the thumb oembed itself stores in the oembed folder in /files

I also decided (again) to go with a custom solution .. using data-src, the oembed thumbnail and the no-cookie domain.
(Not using a consent banner, so the cookies module seemed to heavy for me, although I did not tried)

But still I would welcome the no-cookie domain and the vimeo setting toggle (aka more privacy) for core's external video media type!

I applied the hook that Berdir shared in the first comment but I had to complement the solution by passing the entity id to the iframe controller, that way I was able to load the media entity data. In my case I added a custom field to my Remote Video media type to determine whether to replace youtube.com by youtube-nocookie.com or not.

use Drupal\media\IFrameMarkup;

/**
 * Implements hook_preprocess_media_oembed_iframe().
 */
function mymodule_updates_preprocess_media_oembed_iframe(array &$variables) {
  if (strpos((string) $variables['media'], 'youtube.com') !== FALSE) {
    $entity_id = $variables['entity_id'];
    $remote_video = \Drupal::entityTypeManager()->getStorage('media')->load($entity_id);
    $no_cookies = $remote_video->get('field_nocookies')->value;
    if ($no_cookies) {
      $variables['media'] = IFrameMarkup::create(str_replace('youtube.com/', 'youtube-nocookie.com/', $variables['media']));
    }
  }
}