Uprefix CSS transitions in ui/ and chrome/ styles

ui/login/oobe.css

 /* Copyright 2014 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.
  *
  * This is the stylesheet used by the Out of the box experience (OOBE) flow,
  * sign in and lock screens.
  */
 
 html,
 body {
@@ skipping 18 matching lines @@
 
 button {
   font-family: inherit;
   outline: none;
 }
 
 /* Follow same focus coloring as in widgets.css */
 /* Do not apply this style to restricted button state. */
 button.custom-appearance:not(.button-restricted):not(.button-fancy):not(
     [is="gaia-icon-button"]) {
-  -webkit-transition: border-color 200ms;
   border: 2px solid transparent;
   /* Don't grey out disabled buttons. */
   color: buttontext !important;
+  transition: border-color 200ms;
 }
 
 /* ':focus' used three times to increase specificity. */
 button.custom-appearance:focus:focus:focus {
   border-color: rgba(66, 133, 244, 0.6); /* #4285f4 */
 }
 
 button:not(.custom-appearance) {
   min-width: 72px !important;
 }
@@ skipping 75 matching lines @@
 
 .flexible-label {
   max-width: 250px;
 }
 
 [hidden] {
   display: none !important;
 }
 
 #bubble {
-  -webkit-transition: 250ms opacity;
+  transition: 250ms opacity;
 }
 
 span.bold {
   font-weight: bold;
 }
 
 #version-labels {
-  -webkit-transition: all 500ms linear;
   color: #fff;
   font-size: 11px;
   margin: 10px;
   position: relative;
   text-align: end;
   text-shadow:
       0 0 4px rgba(0,0,0,.6),
       0 1px 2px rgba(0,0,0,.8),
       0 -1px 2px rgba(0,0,0,1);
+  transition: all 500ms linear;
   z-index: 1;
 }
 
 #background {
-  -webkit-transition: 700ms opacity;
   background-size: 100% 100%;
   height: 100%;
   left: 0;
   position: absolute;
   top: 0;
+  transition: 700ms opacity;
   width: 100%;
 }
 
 .background-initial {
   opacity: 0;
 }
 
 .throbber {
   -webkit-margin-end: 0.5em;
   margin-top: 1px;
 }