template_preprocess_html

gistfile1.txt

/**
 * Prepares variables for HTML document templates.
 *
 * Default template: html.html.twig.
 *
 * @param array $variables
 *   An associative array containing:
 *   - page: A render element representing the page.
 *
 * @see system_elements()
 */
function template_preprocess_html(&$variables) {
  $language_interface = language(LANGUAGE_TYPE_INTERFACE); // DC

  // Compile a list of classes that are going to be applied to the body element.
  // This allows advanced theming based on context (home page, node of certain type, etc.).
  $variables['attributes']['class'][] = 'html'; // BAD
  // Add a class that tells us whether we're on the front page or not.
  $variables['attributes']['class'][] = $variables['is_front'] ? 'front'// GOOD : 'not-front'; // BAD
  // Add a class that tells us whether the page is viewed by an authenticated user or not.
  $variables['attributes']['class'][] = $variables['logged_in'] ? 'logged-in' : 'not-logged-in'; // BAD

  // Add information about the number of sidebars.
  if (!empty($variables['page']['sidebar_first']) && !empty($variables['page']['sidebar_second'])) {
    $variables['attributes']['class'][] = 'two-sidebars'; // BAD
  }
  elseif (!empty($variables['page']['sidebar_first'])) {
    $variables['attributes']['class'][] = 'one-sidebar'; // BAD
    $variables['attributes']['class'][] = 'sidebar-first'; // BAD
  }
  elseif (!empty($variables['page']['sidebar_second'])) {
    $variables['attributes']['class'][] = 'one-sidebar'; // BAD
    $variables['attributes']['class'][] = 'sidebar-second'; // BAD
  }
  else {
    $variables['attributes']['class'][] = 'no-sidebars'; // BAD
  }

  // Populate the body classes.
  if ($suggestions = theme_get_suggestions(arg(), 'page', '-')) {
    foreach ($suggestions as $suggestion) {
      if ($suggestion != 'page-front') {
        // Add current suggestion to page classes to make it possible to theme
        // the page depending on the current page type (e.g. node, admin, user,
        // etc.) as well as more specific data like node-12 or node-edit.
        $variables['attributes']['class'][] = drupal_html_class($suggestion); // BAD
      }
    }
  }

  // If on an individual node page, add the node type to body classes.
  if ($node = menu_get_object()) {
    $variables['attributes']['class'][] = drupal_html_class('node-type-' . $node->type); // GOOD
  }

  // Initializes attributes which are specific to the html and body elements.
  $variables['html_attributes'] = new Attribute; // DC

  // HTML element attributes.
  $variables['html_attributes']['lang'] = $language_interface->langcode; // DC
  $variables['html_attributes']['dir'] = $language_interface->direction ? 'rtl' : 'ltr'; // DC

  // Add favicon.
  if (theme_get_setting('features.favicon')) {
    $favicon = theme_get_setting('favicon.url');// GOOD
    $type = theme_get_setting('favicon.mimetype');// GOOD
    drupal_add_html_head_link(array('rel' => 'shortcut icon', 'href' => drupal_strip_dangerous_protocols($favicon), 'type' => $type));// GOOD
  }

  $site_config = config('system.site');// GOOD
  // Construct page title.
  if (drupal_get_title()) {
    $head_title = array(
      'title' => strip_tags(drupal_get_title()),// GOOD
      'name' => check_plain($site_config->get('name')),// GOOD
    );
  }
  else {
    $head_title = array('name' => check_plain($site_config->get('name')));// GOOD
    if ($site_config->get('slogan')) {
      $head_title['slogan'] = strip_tags(filter_xss_admin($site_config->get('slogan')));// GOOD
    }
  }
  $variables['head_title_array'] = $head_title;// GOOD
  $variables['head_title'] = implode(' | ', $head_title);// GOOD

  // Display the html.tpl.php's default mobile metatags for responsive design.
  $elements = array(// GOOD
    'MobileOptimized' => array(
      '#tag' => 'meta',
      '#attributes' => array(
        'name' => 'MobileOptimized',
        'content' => 'width',
      ),
    ),
    'HandheldFriendly' => array(
      '#tag' => 'meta',
      '#attributes' => array(
        'name' => 'HandheldFriendly',
        'content' => 'true',
      ),
    ),
    'viewport' => array(
      '#tag' => 'meta',
      '#attributes' => array(
        'name' => 'viewport',
        'content' => 'width=device-width',
      ),
    ),
    'cleartype' => array(
      '#tag' => 'meta',
      '#attributes' => array(
        'http-equiv' => 'cleartype',
        'content' => 'on',
      ),
    ),
  );
  foreach ($elements as $name => $element) {
    drupal_add_html_head($element, $name);
  }

  // Populate the page template suggestions.
  if ($suggestions = theme_get_suggestions(arg(), 'html')) {// GOOD
    $variables['theme_hook_suggestions'] = $suggestions;
  }
}

Most things in here whether good or bad have little to do with the theme layer, and aside from a few classes can probably be refactored elsewhere. I personally don't consider anything in the head tag to be presentational, FWIW.

Lines 51-54 should be in node.module. Not sure if there's an issue yet.

Lines 122-125 are getting refactored, see http://drupal.org/node/1886448