Print Preview: Fading in/out printing options.

chrome/browser/resources/print_preview_animations.js

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Counter used to give webkit animations unique names.
 var animationCounter = 0;
 
 function addAnimation(code) {
   var name = 'anim' + animationCounter;
   animationCounter++;
   var rules = document.createTextNode(
       '@-webkit-keyframes ' + name + ' {' + code + '}');
   var el = document.createElement('style');
   el.type = 'text/css';
   el.appendChild(rules);
   document.body.appendChild(el);
 
   return name;
 }
 
-function showInvalidHint(el) {
+function fadeInElement(el) {
   if (el.classList.contains('visible'))
     return;
   el.classList.remove('closing');
   el.style.height = 'auto';
   var height = el.offsetHeight;
   el.style.height = height + 'px';
   var animName = addAnimation(
     '0% { opacity: 0; height: 0; } ' +
     '80% { height: ' + (height + 4) + 'px; }' +
     '100% { opacity: 1; height: ' + height + 'px; }');
   el.style.webkitAnimationName = animName;
   el.classList.add('visible');
+  el.addEventListener('webkitAnimationEnd', function() {
+    el.style.height = '';
+    el.style.webkitAnimationName = '';
+  }, false );
 }
 
-function hideInvalidHint(el) {
+function fadeOutElement(el) {
   if (!el.classList.contains('visible'))
     return;
   el.style.webkitAnimationName = '';
   el.classList.add('closing');
   el.classList.remove('visible');
 }