Revert "Gallery: Remove 2x mouse cursor assets temporary."

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 43 matching lines @@
   height: 100%;
   position: absolute;
   width: 100%;
 }
 
 .gallery[tools] .image-container[cursor='default'] {
   cursor: default;
 }
 
 .gallery[tools] .image-container[cursor='move'] {
-  /** TODO(hirono): Take book 2x assets for the mouse cursor.
-      crbug.com/460430 */
-  cursor: url(../images/100/cursor_move.png) 15 15, auto;
+  cursor: -webkit-image-set(
+      url(../images/100/cursor_move.png) 1x,
+      url(../images/200/cursor_move.png) 2x) 15 15, auto;
 }
 
 .gallery[tools] .image-container[cursor='crop'] {
-  /** TODO(hirono): Take book 2x assets for the mouse cursor.
-      crbug.com/460430 */
-  cursor: url(../images/100/cursor_crop.png) 15 15, auto;
+  cursor: -webkit-image-set(
+      url(../images/100/cursor_crop.png) 1x,
+      url(../images/200/cursor_crop.png) 2x) 15 15, auto;
 }
 
 .gallery[tools] .image-container[cursor='n-resize'],
 .gallery[tools] .image-container[cursor='s-resize'] {
-  /** TODO(hirono): Take book 2x assets for the mouse cursor.
-      crbug.com/460430 */
-  cursor: url(../images/100/cursor_updown.png) 15 15, auto;
+  cursor: -webkit-image-set(
+      url(../images/100/cursor_updown.png) 1x,
+      url(../images/200/cursor_updown.png) 2x) 15 15, auto;
 }
 
 .gallery[tools] .image-container[cursor='e-resize'],
 .gallery[tools] .image-container[cursor='w-resize'] {
-  /** TODO(hirono): Take book 2x assets for the mouse cursor.
-      crbug.com/460430 */
-  cursor: url(../images/100/cursor_leftright.png) 15 15, auto;
+  cursor: -webkit-image-set(
+      url(../images/100/cursor_leftright.png) 1x,
+      url(../images/200/cursor_leftright.png) 2x) 15 15, auto;
 }
 
 .gallery[tools] .image-container[cursor='nw-resize'],
 .gallery[tools] .image-container[cursor='se-resize'] {
-  /** TODO(hirono): Take book 2x assets for the mouse cursor.
-      crbug.com/460430 */
-  cursor: url(../images/100/cursor_nwse.png) 15 15, auto;
+  cursor: -webkit-image-set(
+      url(../images/100/cursor_nwse.png) 1x,
+      url(../images/200/cursor_nwse.png) 2x) 15 15, auto;
 }
 
 .gallery[tools] .image-container[cursor='ne-resize'],
 .gallery[tools] .image-container[cursor='sw-resize'] {
-  /** TODO(hirono): Take book 2x assets for the mouse cursor.
-      crbug.com/460430 */
-  cursor: url(../images/100/cursor_swne.png) 15 15, auto;
+  cursor: -webkit-image-set(
+      url(../images/100/cursor_swne.png) 1x,
+      url(../images/200/cursor_swne.png) 2x) 15 15, auto;
 }
 
 .gallery .image-container > .image {
   pointer-events: none;
   position: absolute;
   /* Duration and timing function are set in Javascript. */
   transition-property: -webkit-transform, opacity;
 }
 
 .gallery .image-container > .image[fade] {
@@ skipping 1245 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);
 }