Builds the "contentsCss" configuration part of the CKEditor JS settings.
\Drupal\editor\Plugin\Core\Entity\Editor $editor: A configured text editor object.
array An array containing the "contentsCss" configuration.
getJSSettings()
public function buildContentsCssJSSetting(EditorEntity $editor) {
$css = array(
drupal_get_path('module', 'ckeditor') . '/css/ckeditor-iframe.css',
);
$css = array_merge($css, _ckeditor_theme_css());
drupal_alter('ckeditor_css', $css, $editor);
$css = array_map('file_create_url', $css);
return array_values($css);
}