Reduce webkit CSS prefixes in ui/ styles

ui/file_manager/file_manager/foreground/js/ui/progress_center_panel.js

Index: ui/file_manager/file_manager/foreground/js/ui/progress_center_panel.js
diff --git a/ui/file_manager/file_manager/foreground/js/ui/progress_center_panel.js b/ui/file_manager/file_manager/foreground/js/ui/progress_center_panel.js
index b92a5d7cc425afba75c12ce21f8482e42cd55297..91b5953d32d34dc7fcdef4bad9cb0f1fe7640e78 100644
--- a/ui/file_manager/file_manager/foreground/js/ui/progress_center_panel.js
+++ b/ui/file_manager/file_manager/foreground/js/ui/progress_center_panel.js
@@ -81,7 +81,7 @@ ProgressCenterItemElement.decorate = function(element) {
   element = /** @type {ProgressCenterItemElement} */ (element);
   element.state_ = ProgressItemState.PROGRESSING;
   element.track_ = element.querySelector('.progress-track');
-  element.track_.addEventListener('webkitTransitionEnd',
+  element.track_.addEventListener('transitionend',
                                   element.onTransitionEnd_.bind(element));
   element.cancelTransition_ = null;
   return element;
@@ -259,7 +259,7 @@ function ProgressCenterPanel(element) {
   // Register event handlers.
   element.addEventListener('click', this.onClick_.bind(this));
   element.addEventListener(
-      'webkitAnimationEnd', this.onToggleAnimationEnd_.bind(this));
+      'animationend', this.onToggleAnimationEnd_.bind(this));
   element.addEventListener(
       ProgressCenterItemElement.PROGRESS_ANIMATION_END_EVENT,
       this.onItemAnimationEnd_.bind(this));