Reduce webkit CSS prefixes in ui/ styles

ui/file_manager/video_player/css/media_controls.css

 /* Copyright (c) 2012 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. */
 
 /* Common styles for media buttons. */
 
 .media-button {
   background-position: center;
   background-repeat: no-repeat;
   flex: none;
@@ skipping 176 matching lines @@
 
 .media-button.subtitles:not([showing]) {
   opacity: 0.2;
 }
 
 .media-button.subtitles[unavailable] {
   display: none;
 }
 
 .playback-state-icon {
-  -webkit-animation: none;
+  animation: none;
   background-position: center center;
   background-repeat: no-repeat;
   display: none;
   height: 32px;
   left: 50%;
   margin-left: -16px;
   margin-top: -16px;
   opacity: 0;
   pointer-events: none;
   position: absolute;
@@ skipping 15 matching lines @@
   pointer-events: none;
   position: absolute;
   text-align: center;
   text-shadow: 0 0 10px black;
   top: 20%;
   width: 500px;
   z-index: 2;
 }
 
 .text-banner[visible] {
-  -webkit-animation: text-banner-blowup 3000ms;
+  animation: text-banner-blowup 3000ms;
   display: block;
 }
 
 .playback-state-icon[state] {
   display: block;
 }
 
-@-webkit-keyframes blowup {
+@keyframes blowup {
   from {
     opacity: 1;
   }
   to {
     transform: scale(3);
     opacity: 0;
   }
 }
 
-@-webkit-keyframes text-banner-blowup {
+@keyframes text-banner-blowup {
   from {
     transform: scale(0.5);
     opacity: 0;
   }
   20% {
     transform: scale(1);
     opacity: 0.75;
   }
   80% {
     transform: scale(1);
     opacity: 0.75;
   }
   to {
     transform: scale(3);
     opacity: 0;
   }
 }
 
 .playback-state-icon[state='play'] {
-  -webkit-animation: blowup 500ms;
+  animation: blowup 500ms;
   background-image: -webkit-image-set(
     url(../images/media/media_play_onscreen.png) 1x,
     url(../images/media/2x/media_play_onscreen.png) 2x);
 }
 
 .playback-state-icon[state='pause'] {
-  -webkit-animation: blowup 500ms;
+  animation: blowup 500ms;
   background-image: -webkit-image-set(
     url(../images/media/media_pause_onscreen.png) 1x,
     url(../images/media/2x/media_pause_onscreen.png) 2x);
 }