[filebrowser] Save sorting field/order for modal dialogs, show spinner when scanning directories.

chrome/browser/resources/file_manager/css/file_manager.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.
  */
 
 /* Outer frame of the dialog. */
 body {
    -webkit-box-flex: 1;
    -webkit-box-orient: vertical;
@@ skipping 399 matching lines @@
   -webkit-box-orient: vertical;
   -webkit-box-flex: 1;
 }
 
 .list-container {
   display: -webkit-box;
   -webkit-box-flex: 1;
   position: relative;
 }
 
+.spinner {
+  width: 22px;
+  height: 22px;
+  position: absolute;
+  left: 50%;
+  top: 50%;
+  margin-left: -11px;
+  margin-top: -11px;
+  background-image: url(../images/spinner.svg);
+  background-size: 100%;
+  opacity: 0.5;
+}
+
 .downloads-warning {
   display: -webkit-box;
   -webkit-box-orient: horizontal;
   height: 57px;
   background-color: #f0f0f0;
   font-size: 13px;
   color: #666;
   -webkit-box-align: center;
   overflow: hidden;
   -webkit-transition: height 70ms linear;
@@ skipping 445 matching lines @@
 /* Overlay pane covering the entire file manager window (e.g. image editor)*/
 .overlay-pane {
   position: absolute;
   top: 0;
   left: 0;
   width: 100%;
   height: 100%;
   border: none;
   z-index: 100;
 }