Reduce webkit CSS prefixes in ui/ styles

ui/login/account_picker/user_pod_row.js

Index: ui/login/account_picker/user_pod_row.js
diff --git a/ui/login/account_picker/user_pod_row.js b/ui/login/account_picker/user_pod_row.js
index 71e88f292fade6756b7ce5bcca209238bf3dcd79..79225f48c6021d3c4df109a35abc8bb367599b42 100644
--- a/ui/login/account_picker/user_pod_row.js
+++ b/ui/login/account_picker/user_pod_row.js
@@ -2021,8 +2021,8 @@ cr.define('login', function() {
 
       var self = this;
       this.classList.add('animating');
-      this.addEventListener('webkitTransitionEnd', function f(e) {
-        self.removeEventListener('webkitTransitionEnd', f);
+      this.addEventListener('transitionend', function f(e) {
+        self.removeEventListener('transitionend', f);
         self.classList.remove('animating');
 
         // Accessibility focus indicator does not move with the focused
@@ -2235,9 +2235,9 @@ cr.define('login', function() {
       setTimeout(function() {
         pod.classList.add('advanced');
         pod.makeSpaceForExpandedPod_();
-        languageAndInputSection.addEventListener('webkitTransitionEnd',
+        languageAndInputSection.addEventListener('transitionend',
                                                  function observer() {
-          languageAndInputSection.removeEventListener('webkitTransitionEnd',
+          languageAndInputSection.removeEventListener('transitionend',
                                                       observer);
           pod.classList.remove('transitioning-to-advanced');
           pod.querySelector('.language-select').focus();
@@ -3660,8 +3660,8 @@ cr.define('login', function() {
       if (focusedPod) {
         var screen = this.parentNode;
         var self = this;
-        focusedPod.addEventListener('webkitTransitionEnd', function f(e) {
-          focusedPod.removeEventListener('webkitTransitionEnd', f);
+        focusedPod.addEventListener('transitionend', function f(e) {
+          focusedPod.removeEventListener('transitionend', f);
           focusedPod.reset(true);
           // Notify screen that it is ready.
           screen.onShow();