HiDPI assets for Chrome OS Files app

chrome/browser/resources/file_manager/css/photo_import.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. */
 
 .photo-import {
   -webkit-user-select: none;
   background: black;
   bottom: 0;
   color: white;
   font-family: Open Sans, Droid Sans Fallback, sans-serif;
@@ skipping 83 matching lines @@
 }
 
 button.import[pressed] {
   /* TODO */
   background-image: url(../images/gallery/icon_crop_selected.png);
 }
 
 
 
 .spinner {
-  background-image: url(../images/gallery/spinner_white.svg);
+  background-image: url(../images/common/spinner_white.svg);
   background-size: 100%;
   height: 22px;
   left: 50%;
   margin-left: -11px;
   margin-top: -11px;
   position: absolute;
   top: 50%;
   width: 22px;
 }
 
@@ skipping 65 matching lines @@
   -webkit-user-drag: none;
   border: 2px solid transparent;
   box-sizing: border-box;
   position: absolute;
 }
 
 .grid-item[selected] img,
 .grid-item:hover img {
   outline: 2px solid rgb(51, 153, 255);
 }