Reduce webkit CSS prefixes in ui/ styles

ui/file_manager/file_manager/foreground/css/common.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. */
 
 /* Special attribute to hide elements. */
 [hidden] {
   display: none !important;
 }
 
 /* "chrome-menu" class overrides some standard menu.css styles, to make custom
@@ skipping 209 matching lines @@
   flex-direction: column;
   padding: 12px;
   position: relative;
   width: 386px;
 }
 
 .cr-dialog-frame:focus {
   outline: none;
 }
 
-@-webkit-keyframes pulse {
+@keyframes pulse {
  0% {
    transform: scale(1);
  }
  40% {
    transform: scale(1.02);
   }
  60% {
    transform: scale(1.02);
   }
  100% {
    transform: scale(1);
  }
 }
 
 .cr-dialog-frame.pulse {
-  -webkit-animation-duration: 180ms;
-  -webkit-animation-iteration-count: 1;
-  -webkit-animation-name: pulse;
-  -webkit-animation-timing-function: ease-in-out;
+  animation-duration: 180ms;
+  animation-iteration-count: 1;
+  animation-name: pulse;
+  animation-timing-function: ease-in-out;
 }
 
 .shown > .cr-dialog-frame {
   opacity: 1;
 }
 
 .cr-dialog-frame {
   opacity: 0;
   transition: opacity 250ms;
 }
@@ skipping 88 matching lines @@
   .table-row-cell .size,
   .table-row-cell .type,
   .table-row-cell .date,
   .thumbnail-bottom .filename-label,
   .autocomplete-suggestions > li > .detail-text {
     /* In HiDPI display, 13pt Roboto font is drawn upper than normal display,
      * so add extra padding on top of it. */
     padding-top: 3px;
   }
 }