Gallery: Support RAW files in Gallery.

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-size: 84%;
   margin: 0;
 }
 
@@ skipping 365 matching lines @@
   opacity: 0.5;
 }
 
 .gallery[editing] .filename-spacer .overwrite-original,
 .gallery[editing] .filename-spacer .overwrite-original > * {
   cursor: pointer;
   opacity: 1;
   pointer-events: auto;
 }
 
-.gallery[editing] .options[saved] .overwrite-original {
+.gallery[editing] .overwrite-original[disabled] {
   opacity: 0.5;
 }
 
-.gallery[editing] .options[saved] .overwrite-original,
-.gallery[editing] .options[saved] .overwrite-original > * {
+.gallery[editing] .overwrite-original[disabled],
+.gallery[editing] .overwrite-original[disabled] > * {
   cursor: default;
   pointer-events: none;
 }
 
 .gallery .filename-spacer .saved[highlighted] {
   -webkit-transform: scaleX(1.1) scaleY(1.1) rotate(0);
   opacity: 1;
 }
 
 /* Bubble */
@@ skipping 954 matching lines @@
   background-color: rgba(255, 0, 0, 0.3);
 }
 
 .debug-me .load-target-external-metadata::before {
   background-color: rgba(0, 255, 0, 0.3);
 }
 
 .debug-me .load-target-file-entry::before {
   background-color: rgba(0, 0, 255, 0.3);
 }