Files.app: Move VP/Galllery related files to dedicate folders

ui/file_manager/gallery/css/gallery.css

 /* Copyright (c) 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. */
 
 body {
   -webkit-user-select: none;
   font-family: Noto Sans UI, sans-serif;
   font-size: 84%;
   margin: 0;
 }
@@ skipping 1110 matching lines @@
 .gallery:not([spinner]) .spinner {
   display: none;
 }
 
 .gallery .error-banner {
   -webkit-box-align: center;
   -webkit-box-orient: horizontal;
   -webkit-box-pack: center;
   background-color: rgba(24, 24, 24, 1);
   background-image: -webkit-image-set(
-      url(../../file_manager/foreground/images/media/error.png) 1x,
-      url(../../file_manager/foreground/images/media/2x/error.png) 2x);
+      url(../images/100/error.png) 1x,
+      url(../images/200/error.png) 2x);
   background-position: 25px center;
   background-repeat: no-repeat;
   color: white;
   display: -webkit-box;
   height: 54px;
   padding-left: 70px;
   padding-right: 35px;
 }
 
 .gallery:not([error]) .error-banner {
@@ skipping 188 matching lines @@
       url(chrome://resources/images/2x/apps/topbar_button_maximize.png) 2x)
       center;
 }
 
 .gallery > .header > .close-button {
   background: -webkit-image-set(
       url(chrome://resources/images/apps/topbar_button_close.png) 1x,
       url(chrome://resources/images/2x/apps/topbar_button_close.png) 2x)
       center;
 }