diff --git a/core/misc/form.js b/core/misc/form.js
index c0c5f08..766b159 100644
--- a/core/misc/form.js
+++ b/core/misc/form.js
@@ -1,43 +1,21 @@
-(function ($) {
+(function ($, Drupal, debounce) {
 
 "use strict";
 
-/**
- * Retrieves the summary for the first element.
- */
-$.fn.drupalGetSummary = function () {
-  var callback = this.data('summaryCallback');
-  return (this[0] && callback) ? $.trim(callback(this[0])) : '';
-};
-
-/**
- * Sets the summary for all matched elements.
- *
- * @param callback
- *   Either a function that will be called each time the summary is
- *   retrieved or a string (which is returned each time).
- */
-$.fn.drupalSetSummary = function (callback) {
-  var self = this;
-
-  // To facilitate things, the callback should always be a function. If it's
-  // not, we wrap it into an anonymous function which just returns the value.
-  if (typeof callback !== 'function') {
-    var val = callback;
-    callback = function () { return val; };
+Drupal.form = {
+  serialize: function (form) {
+    return $(form).serialize();
+  },
+  changed: function (form) {
+    var $form = $(form);
+    var previousValues = $form.attr('data-drupal-form-values');
+    var currentValues = Drupal.form.serialize(form);
+    $form.attr('data-drupal-form-values', currentValues);
+    if (!previousValues) {
+      return false;
+    }
+    return previousValues !== currentValues;
   }
-
-  return this
-    .data('summaryCallback', callback)
-    // To prevent duplicate events, the handlers are first removed and then
-    // (re-)added.
-    .off('formUpdated.summary')
-    .on('formUpdated.summary', function () {
-      self.trigger('summaryUpdated');
-    })
-    // The actual summaryUpdated handler doesn't fire when the callback is
-    // changed, so we have to do this manually.
-    .trigger('summaryUpdated');
 };
 
 /**
@@ -45,17 +23,19 @@ $.fn.drupalSetSummary = function (callback) {
  */
 Drupal.behaviors.formUpdated = {
   attach: function (context) {
-    // These events are namespaced so that we can remove them later.
-    var events = 'change.formUpdated click.formUpdated blur.formUpdated keyup.formUpdated';
-    $(context)
-      // Since context could be an input element itself, it's added back to
-      // the jQuery object and filtered again.
-      .find(':input').addBack().filter(':input')
-      // To prevent duplicate events, the handlers are first removed and then
-      // (re-)added.
-      .off(events).on(events, function () {
-        $(this).trigger('formUpdated');
-      });
+    // Binds to forms and not the whole page to avoid too much messing around.
+
+    function checkFormUpdated (e) {
+      var $form = $(e.currentTarget);
+      if (Drupal.form.changed(e.currentTarget)) {
+        $form.trigger('formUpdated');
+      }
+    }
+
+    var events = 'change.formUpdated keyup.formUpdated load.formUpdated';
+
+    $('body').once('form-updated').on(events, 'form', debounce(checkFormUpdated, 500));
+
   }
 };
 
@@ -99,15 +79,17 @@ Drupal.behaviors.formUpdated = {
  */
 Drupal.behaviors.formSingleSubmit = {
   attach: function (context) {
-    function onFormSubmit(e) {
+
+    function onFormSubmit (e) {
       var $form = $(e.currentTarget);
-      var formValues = $form.serialize();
+      var currentValues = Drupal.form.serialize(e.currentTarget);
       var previousValues = $form.attr('data-drupal-form-submit-last');
-      if (previousValues === formValues) {
+
+      if (currentValues === previousValues) {
         e.preventDefault();
       }
       else {
-        $form.attr('data-drupal-form-submit-last', formValues);
+        $form.attr('data-drupal-form-submit-last', currentValues);
       }
     }
 
@@ -115,24 +97,4 @@ Drupal.behaviors.formSingleSubmit = {
   }
 };
 
-/**
- * Prepopulate form fields with information from the visitor cookie.
- */
-Drupal.behaviors.fillUserInfoFromCookie = {
-  attach: function (context, settings) {
-    var userInfo = ['name', 'mail', 'homepage'];
-    $('form.user-info-from-cookie').once('user-info-from-cookie', function () {
-      var $formContext = $(this);
-      var i, il, $element, cookie;
-      for (i = 0, il = userInfo.length; i < il; i += 1) {
-        $element = $formContext.find('[name=' + userInfo[i] + ']');
-        cookie = $.cookie('Drupal.visitor.' + userInfo[i]);
-        if ($element.length && cookie) {
-          $element.val(cookie);
-        }
-      }
-    });
-  }
-};
-
-})(jQuery);
+})(jQuery, Drupal, Drupal.debounce);
diff --git a/core/modules/system/system.module b/core/modules/system/system.module
index 9500adf..10c97d4 100644
--- a/core/modules/system/system.module
+++ b/core/modules/system/system.module
@@ -973,11 +973,12 @@ function system_library_info() {
     'version' => \Drupal::VERSION,
     'js' => array(
       'core/misc/form.js' => array('group' => JS_LIBRARY, 'weight' => 1),
+      'core/misc/form.summary.js' => array('group' => JS_LIBRARY, 'weight' => 1),
     ),
     'dependencies' => array(
       array('system', 'jquery'),
       array('system', 'drupal'),
-      array('system', 'jquery.cookie'),
+      array('system', 'drupal.debounce'),
       array('system', 'jquery.once'),
     ),
   );
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 6744e9e..d95d088 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -1925,6 +1925,19 @@ function user_library_info() {
     ),
   );
 
+  $libraries['drupal.user.info'] = array(
+    'title' => 'User',
+    'version' => \Drupal::VERSION,
+    'js' => array(
+      $path . '/user.infos.js' => array(),
+    ),
+    'dependencies' => array(
+      array('system', 'jquery'),
+      array('system', 'drupal'),
+      array('system', 'jquery.cookie'),
+    ),
+  );
+
   $libraries['drupal.user.permissions'] = array(
     'title' => 'User permissions',
     'version' => \Drupal::VERSION,