Added @media print rules to gallery.css to make the picture look better on a printed page

chrome/browser/resources/file_manager/css/gallery.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. */
 
 body {
   -webkit-user-select: none;
   font-family: Open Sans, Droid Sans Fallback, sans-serif;
   font-size: 84%;
   margin: 0;
 }
@@ skipping 897 matching lines @@
 }
 
 .gallery .share-menu > div > img {
   display: block;
   margin-right: 5px;
 }
 
 /* Load spinner and error banner */
 
 .gallery .spinner {
-  background-image: url('../images/common/spinner_white.svg);
+  background-image: url('../images/common/spinner_white.svg');
   background-size: 100%;
   height: 32px;
   left: 50%;
   margin-left: -16px;
   margin-top: -16px;
   opacity: 0.5;
   position: absolute;
   top: 50%;
   width: 32px;
 }
@@ skipping 62 matching lines @@
 
 .gallery[video] .video-controls {
   -webkit-box-flex: 1;
   display: -webkit-box;
 }
 
 .gallery[video] > .toolbar .button.edit,
 .gallery[video] > .toolbar .edit-bar {
   display: none;
 }
+
+@media print {
+  .image-container > .image {
+    left: 0 !important;
+    max-height: 100%;
+    max-width: 100%;
+    object-fit: contain;
+    top: 0 !important;
+  }
+
+  .gallery .tool {
+    opacity: 0 !important;
+  }
+}