diff --git a/core/modules/taxonomy/lib/Drupal/taxonomy/Form/OverviewTerms.php b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/OverviewTerms.php
new file mode 100644
index 0000000..a557063
--- /dev/null
+++ b/core/modules/taxonomy/lib/Drupal/taxonomy/Form/OverviewTerms.php
@@ -0,0 +1,516 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\taxonomy\Form\OverviewTerms
+ */
+
+namespace Drupal\taxonomy\Form;
+
+use Drupal\Core\Form\FormInterface;
+use Drupal\Core\Controller\ControllerInterface;
+use Drupal\Core\Entity\EntityManager;
+use Drupal\Core\Config\ConfigFactory;
+use Drupal\Core\Database\Connection;
+use Drupal\Core\Extension\ModuleHandlerInterface;
+use Drupal\Core\StringTranslation\TranslationManager;
+use Drupal\taxonomy\VocabularyInterface;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/*
+ * Provides terms overview form for a taxonomy vocabulary.
+ */
+class OverviewTerms implements ControllerInterface, FormInterface {
+
+  /**
+   * Entity Manager.
+   *
+   * @var \Drupal\Core\Entity\EntityManager
+   */
+  protected $entityManager;
+
+  /**
+   * Taxonomy config.
+   *
+   * @var \Drupal\Core\Config\Config
+   */
+  protected $config;
+
+  /**
+   * Current database connection.
+   *
+   * @var \Drupal\Core\Database\Connection
+   */
+  protected $database;
+
+  /**
+   * Current request.
+   *
+   * @var \Symfony\Component\HttpFoundation\Request
+   */
+  protected $request;
+
+  /**
+   * The module handler service.
+   *
+   * @var \Drupal\Core\Extension\ModuleHandlerInterface
+   */
+  protected $moduleHandler;
+
+  /**
+   * The translation manager service.
+   *
+   * @var \Drupal\Core\StringTranslation\TranslationManager
+   */
+  protected $translation;
+
+  /**
+   * Constructs an OverviewTerms object.
+   *
+   * @param \Drupal\Core\Entity\EntityManager $entity_manager
+   *   The entity manager service.
+   * @param \Drupal\Core\Config\ConfigFactory $config_factory
+   *   The config factory service.
+   * @param \Drupal\Core\Database\Connection $connection
+   *   The current database connection.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request.
+   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
+   *   The module handler service.
+   * @param \Drupal\Core\StringTranslation\TranslationManager $translation
+   *   The translation manager.
+   */
+  public function __construct(EntityManager $entity_manager, ConfigFactory $config_factory, Connection $connection, Request $request, ModuleHandlerInterface $module_handler, TranslationManager $translation) {
+    $this->entityManager = $entity_manager;
+    $this->config = $config_factory->get('taxonomy.settings');
+    $this->database = $connection;
+    $this->request = $request;
+    $this->moduleHandler = $module_handler;
+    $this->translation = $translation;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('plugin.manager.entity'),
+      $container->get('config.factory'),
+      $container->get('database'),
+      $container->get('request'),
+      $container->get('module_handler'),
+      $container->get('string_translation')
+    );
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() {
+    return 'taxonomy_overview_terms';
+  }
+
+  /**
+   * Form constructor.
+   *
+   * Display a tree of all the terms in a vocabulary, with options to edit
+   * each one. The form is made drag and drop by the theme function.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param array $form_state
+   *   An associative array containing the current state of the form.
+   * @param \Drupal\taxonomy\VocabularyInterface $taxonomy_vocabulary
+   *   The vocabulary to display the overview form for.
+   *
+   * @return array
+   *   The form structure.
+   */
+  public function buildForm(array $form, array &$form_state, VocabularyInterface $taxonomy_vocabulary = NULL) {
+    // @todo Remove global variables when http://drupal.org/node/2044435 is in.
+    global $pager_page_array, $pager_total, $pager_total_items;
+
+    $form_state['taxonomy']['vocabulary'] = $taxonomy_vocabulary;
+    $parent_fields = FALSE;
+
+    ($page = $this->request->query->get('page')) ?: 0;
+    // Number of terms per page.
+    $page_increment = $this->config->get('terms_per_page_admin');
+    // Elements shown on this page.
+    $page_entries = 0;
+    // Elements at the root level before this page.
+    $before_entries = 0;
+    // Elements at the root level after this page.
+    $after_entries = 0;
+    // Elements at the root level on this page.
+    $root_entries = 0;
+
+    // Terms from previous and next pages are shown if the term tree would have
+    // been cut in the middle. Keep track of how many extra terms we show on
+    // each page of terms.
+    $back_step = NULL;
+    $forward_step = 0;
+
+    // An array of the terms to be displayed on this page.
+    $current_page = array();
+
+    $delta = 0;
+    $term_deltas = array();
+    // @todo taxonomy_get_tree needs to be converted to a service and injected.
+    //   Will be fixed in http://drupal.org/node/1976298.
+    $tree = taxonomy_get_tree($taxonomy_vocabulary->id(), 0, NULL, TRUE);
+    $term = current($tree);
+    do {
+      // In case this tree is completely empty.
+      if (empty($term)) {
+        break;
+      }
+      $delta++;
+      // Count entries before the current page.
+      if ($page && ($page * $page_increment) > $before_entries && !isset($back_step)) {
+        $before_entries++;
+        continue;
+      }
+      // Count entries after the current page.
+      elseif ($page_entries > $page_increment && isset($complete_tree)) {
+        $after_entries++;
+        continue;
+      }
+
+      // Do not let a term start the page that is not at the root.
+      if (isset($term->depth) && ($term->depth > 0) && !isset($back_step)) {
+        $back_step = 0;
+        while ($pterm = prev($tree)) {
+          $before_entries--;
+          $back_step++;
+          if ($pterm->depth == 0) {
+            prev($tree);
+            // Jump back to the start of the root level parent.
+            continue 2;
+          }
+        }
+      }
+      $back_step = isset($back_step) ? $back_step : 0;
+
+      // Continue rendering the tree until we reach the a new root item.
+      if ($page_entries >= $page_increment + $back_step + 1 && $term->depth == 0 && $root_entries > 1) {
+        $complete_tree = TRUE;
+        // This new item at the root level is the first item on the next page.
+        $after_entries++;
+        continue;
+      }
+      if ($page_entries >= $page_increment + $back_step) {
+        $forward_step++;
+      }
+
+      // Finally, if we've gotten down this far, we're rendering a term on this
+      // page.
+      $page_entries++;
+      $term_deltas[$term->id()] = isset($term_deltas[$term->id()]) ? $term_deltas[$term->id()] + 1 : 0;
+      $key = 'tid:' . $term->id() . ':' . $term_deltas[$term->id()];
+
+      // Keep track of the first term displayed on this page.
+      if ($page_entries == 1) {
+        $form['#first_tid'] = $term->id();
+      }
+      // Keep a variable to make sure at least 2 root elements are displayed.
+      if ($term->parents[0] == 0) {
+        $root_entries++;
+      }
+      $current_page[$key] = $term;
+    } while ($term = next($tree));
+
+    // Because we didn't use a pager query, set the necessary pager variables.
+    $total_entries = $before_entries + $page_entries + $after_entries;
+    $pager_total_items[0] = $total_entries;
+    $pager_page_array[0] = $page;
+    $pager_total[0] = ceil($total_entries / $page_increment);
+
+    // If this form was already submitted once, it's probably hit a validation
+    // error. Ensure the form is rebuilt in the same order as the user
+    // submitted.
+    if (!empty($form_state['input'])) {
+      // Get the $_POST order.
+      $order = array_flip(array_keys($form_state['input']['terms']));
+      // Update our form with the new order.
+      $current_page = array_merge($order, $current_page);
+      foreach ($current_page as $key => $term) {
+        // Verify this is a term for the current page and set at the current
+        // depth.
+        if (is_array($form_state['input']['terms'][$key]) && is_numeric($form_state['input']['terms'][$key]['term']['tid'])) {
+          $current_page[$key]->depth = $form_state['input']['terms'][$key]['term']['depth'];
+        }
+        else {
+          unset($current_page[$key]);
+        }
+      }
+    }
+
+    $errors = form_get_errors() != FALSE ? form_get_errors() : array();
+    $destination = drupal_get_destination();
+    $row_position = 0;
+    // Build the actual form.
+    $form['terms'] = array(
+      '#type' => 'table',
+      '#header' => array($this->translation->translate('Name'), $this->translation->translate('Weight'), $this->translation->translate('Operations')),
+      '#empty' => $this->translation->translate('No terms available. <a href="@link">Add term</a>.', array('@link' => url('admin/structure/taxonomy/manage/' . $taxonomy_vocabulary->id() . '/add'))),
+      '#attributes' => array(
+        'id' => 'taxonomy',
+      ),
+    );
+    foreach ($current_page as $key => $term) {
+      $uri = $term->uri();
+      $edit_uri = $term->uri('edit-form');
+      $form['terms'][$key]['#term'] = $term;
+      $indentation = array();
+      if (isset($term->depth) && $term->depth > 0) {
+        $indentation = array(
+          '#theme' => 'indentation',
+          '#size' => $term->depth,
+        );
+      }
+      $form['terms'][$key]['term'] = array(
+        '#prefix' => !empty($indentation) ? drupal_render($indentation) : '',
+        '#type' => 'link',
+        '#title' => $term->label(),
+        '#href' => $uri['path'],
+      );
+      if ($taxonomy_vocabulary->hierarchy != TAXONOMY_HIERARCHY_MULTIPLE && count($tree) > 1) {
+        $parent_fields = TRUE;
+        $form['terms'][$key]['term']['tid'] = array(
+          '#type' => 'hidden',
+          '#value' => $term->id(),
+          '#attributes' => array(
+            'class' => array('term-id'),
+          ),
+        );
+        $form['terms'][$key]['term']['parent'] = array(
+          '#type' => 'hidden',
+          // Yes, default_value on a hidden. It needs to be changeable by the
+          // javascript.
+          '#default_value' => $term->parent->value,
+          '#attributes' => array(
+            'class' => array('term-parent'),
+          ),
+        );
+        $form['terms'][$key]['term']['depth'] = array(
+          '#type' => 'hidden',
+          // Same as above, the depth is modified by javascript, so it's a
+          // default_value.
+          '#default_value' => $term->depth,
+          '#attributes' => array(
+            'class' => array('term-depth'),
+          ),
+        );
+      }
+      $form['terms'][$key]['weight'] = array(
+        '#type' => 'weight',
+        '#delta' => $delta,
+        '#title_display' => 'invisible',
+        '#title' => $this->translation->translate('Weight for added term'),
+        '#default_value' => $term->weight->value,
+        '#attributes' => array(
+          'class' => array('term-weight'),
+        ),
+      );
+      $operations = array(
+        'edit' => array(
+          'title' => $this->translation->translate('edit'),
+          'href' => $edit_uri['path'],
+          'query' => $destination,
+        ),
+        'delete' => array(
+          'title' => $this->translation->translate('delete'),
+          'href' => $uri['path'] . '/delete',
+          'query' => $destination,
+        ),
+      );
+      if ($this->moduleHandler->invoke('content_translation', 'translate_access', array($term))) {
+        $operations['translate'] = array(
+          'title' => $this->translation->translate('translate'),
+          'href' => $uri['path'] . '/translations',
+          'query' => $destination,
+        );
+      }
+      $form['terms'][$key]['operations'] = array(
+        '#type' => 'operations',
+        '#links' => $operations,
+      );
+
+      $form['terms'][$key]['#attributes']['class'] = array();
+      if ($parent_fields) {
+        $form['terms'][$key]['#attributes']['class'][] = 'draggable';
+      }
+
+      // Add classes that mark which terms belong to previous and next pages.
+      if ($row_position < $back_step || $row_position >= $page_entries - $forward_step) {
+        $form['terms'][$key]['#attributes']['class'][] = 'taxonomy-term-preview';
+      }
+
+      if ($row_position !== 0 && $row_position !== count($tree) - 1) {
+        if ($row_position == $back_step - 1 || $row_position == $page_entries - $forward_step - 1) {
+          $form['terms'][$key]['#attributes']['class'][] = 'taxonomy-term-divider-top';
+        }
+        elseif ($row_position == $back_step || $row_position == $page_entries - $forward_step) {
+          $form['terms'][$key]['#attributes']['class'][] = 'taxonomy-term-divider-bottom';
+        }
+      }
+
+      // Add an error class if this row contains a form error.
+      foreach ($errors as $error_key => $error) {
+        if (strpos($error_key, $key) === 0) {
+          $form['terms'][$key]['#attributes']['class'][] = 'error';
+        }
+      }
+      $row_position++;
+    }
+
+    if ($parent_fields) {
+      $form['terms']['#tabledrag'][] = array(
+        'match',
+        'parent',
+        'term-parent',
+        'term-parent',
+        'term-id',
+        FALSE,
+      );
+      $form['terms']['#tabledrag'][] = array(
+        'depth',
+        'group',
+        'term-depth',
+        NULL,
+        NULL,
+        FALSE
+      );
+      $form['terms']['#attached']['library'][] = array('taxonomy', 'drupal.taxonomy');
+      $form['terms']['#attached']['js'][] = array(
+        'data' => array('taxonomy' => array('backStep' => $back_step, 'forwardStep' => $forward_step)),
+        'type' => 'setting',
+      );
+    }
+    $form['terms']['#tabledrag'][] = array('order', 'sibling', 'term-weight');
+
+    if ($taxonomy_vocabulary->hierarchy != TAXONOMY_HIERARCHY_MULTIPLE && count($tree) > 1) {
+      $form['actions'] = array('#type' => 'actions', '#tree' => FALSE);
+      $form['actions']['submit'] = array(
+        '#type' => 'submit',
+        '#value' => $this->translation->translate('Save'),
+        '#button_type' => 'primary',
+      );
+      $form['actions']['reset_alphabetical'] = array(
+        '#type' => 'submit',
+        '#value' => $this->translation->translate('Reset to alphabetical')
+      );
+      $form_state['redirect'] = array(current_path(), ($page ? array('query' => array('page' => $page)) : array()));
+    }
+
+    return $form;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function validateForm(array &$form, array &$form_state) {}
+
+  /**
+   * Form submission handler.
+   *
+   * Rather than using a textfield or weight field, this form depends entirely
+   * upon the order of form elements on the page to determine new weights.
+   *
+   * Because there might be hundreds or thousands of taxonomy terms that need to
+   * be ordered, terms are weighted from 0 to the number of terms in the
+   * vocabulary, rather than the standard -10 to 10 scale. Numbers are sorted
+   * lowest to highest, but are not necessarily sequential. Numbers may be
+   * skipped when a term has children so that reordering is minimal when a child
+   * is added or removed from a term.
+   *
+   * @param array $form
+   *   An associative array containing the structure of the form.
+   * @param array $form_state
+   *   An associative array containing the current state of the form.
+   */
+  public function submitForm(array &$form, array &$form_state) {
+    // Sort term order based on weight.
+    uasort($form_state['values']['terms'], 'drupal_sort_weight');
+
+    $vocabulary = $form_state['taxonomy']['vocabulary'];
+    // Update the current hierarchy type as we go.
+    $hierarchy = TAXONOMY_HIERARCHY_DISABLED;
+
+    $changed_terms = array();
+    // @todo taxonomy_get_tree needs to be converted to a service and injected.
+    //   Will be fixed in http://drupal.org/node/1976298.
+    $tree = taxonomy_get_tree($vocabulary->id(), 0, NULL, TRUE);
+
+    if (empty($tree)) {
+      return;
+    }
+
+    // Build a list of all terms that need to be updated on previous pages.
+    $weight = 0;
+    $term = $tree[0];
+    while ($term->id() != $form['#first_tid']) {
+      if ($term->parent->value == 0 && $term->weight->value != $weight) {
+        $term->weight->value = $weight;
+        $changed_terms[$term->id()] = $term;
+      }
+      $weight++;
+      $hierarchy = $term->parent->value != 0 ? TAXONOMY_HIERARCHY_SINGLE : $hierarchy;
+      $term = $tree[$weight];
+    }
+
+    // Renumber the current page weights and assign any new parents.
+    $level_weights = array();
+    foreach ($form_state['values']['terms'] as $tid => $values) {
+      if (isset($form['terms'][$tid]['#term'])) {
+        $term = $form['terms'][$tid]['#term'];
+        // Give terms at the root level a weight in sequence with terms on previous pages.
+        if ($values['term']['parent'] == 0 && $term->weight->value != $weight) {
+          $term->weight->value = $weight;
+          $changed_terms[$term->id()] = $term;
+        }
+        // Terms not at the root level can safely start from 0 because they're all on this page.
+        elseif ($values['term']['parent'] > 0) {
+          $level_weights[$values['term']['parent']] = isset($level_weights[$values['term']['parent']]) ? $level_weights[$values['term']->parent->value] + 1 : 0;
+          if ($level_weights[$values['term']['parent']] != $term->weight->value) {
+            $term->weight->value = $level_weights[$values['term']['parent']];
+            $changed_terms[$term->id()] = $term;
+          }
+        }
+        // Update any changed parents.
+        if ($values['term']['parent'] != $term->parent->value) {
+          $term->parent->value = $values['term']['parent'];
+          $changed_terms[$term->id()] = $term;
+        }
+        $hierarchy = $term->parent->value != 0 ? TAXONOMY_HIERARCHY_SINGLE : $hierarchy;
+        $weight++;
+      }
+    }
+
+    // Build a list of all terms that need to be updated on following pages.
+    for ($weight; $weight < count($tree); $weight++) {
+      $term = $tree[$weight];
+      if ($term->parent->value == 0 && $term->weight->value != $weight) {
+        $term->parent->value = $term->parent->value;
+        $term->weight->value = $weight;
+        $changed_terms[$term->id()] = $term;
+      }
+      $hierarchy = $term->parent->value != 0 ? TAXONOMY_HIERARCHY_SINGLE : $hierarchy;
+    }
+
+    // Save all updated terms.
+    foreach ($changed_terms as $term) {
+      $term->save();
+    }
+
+    // Update the vocabulary hierarchy to flat or single hierarchy.
+    if ($vocabulary->hierarchy != $hierarchy) {
+      $vocabulary->hierarchy = $hierarchy;
+      $vocabulary->save();
+    }
+    drupal_set_message($this->translation->translate('The configuration options have been saved.'));
+  }
+
+}