chrome/browser/resources/shared/css/spinner.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. */

.inline-spinner,
.spinner {
  -webkit-animation: spinner-animation 1s step-end infinite;
  background-image: url('chrome://resources/images/spinner.svg');
  background-size: 100%;
}

.inline-spinner {
  display: inline-block;
  height: 16px;
  width: 16px;
}

.spinner {
  height: 22px;
  width: 22px;
}

@-webkit-keyframes spinner-animation {
  0% {
    -webkit-transform: rotate(0deg);
  }
  8.33% {
    -webkit-transform: rotate(30deg);
  }
  16.67%  {
    -webkit-transform: rotate(60deg);
  }
  25%  {
    -webkit-transform: rotate(90deg);
  }
  33.33%  {
    -webkit-transform: rotate(120deg);
  }
  41.67%  {
    -webkit-transform: rotate(150deg);
  }
  50%  {
    -webkit-transform: rotate(180deg);
  }
  58.33%  {
    -webkit-transform: rotate(210deg);
  }
  66.67%  {
    -webkit-transform: rotate(240deg);
  }
  75%  {
    -webkit-transform: rotate(270deg);
  }
  83.33%  {
    -webkit-transform: rotate(300deg);
  }
  91.67%  {
    -webkit-transform: rotate(330deg);
  }
}