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 6d498d989998cd154077f0eebf2762ea5bcc1e7f..3d4bfab89ceae8201e87638c4c565c552e59d4ea 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;
@@ -260,7 +260,7 @@ 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));