Gallery: Enlarge the size of range inputs 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-family: Open Sans, Droid Sans Fallback, sans-serif;
   font-size: 84%;
   margin: 0;
 }
@@ skipping 865 matching lines @@
 }
 
 .gallery .edit-modal button.selected,
 .gallery .edit-modal button:active {
   background: #f0f0f0;
   color: black;
 }
 
 .gallery .edit-modal .range {
   -webkit-appearance: none !important;
+  background: transparent;
+  height: 29px;
+  margin-right: 10px;
+  position: relative;
+}
+
+.gallery .edit-modal .range::before {
+  background: #fff;
+  content: '';
+  display: block;
   height: 3px;
-  margin-right: 10px;
-  margin-top: 1px;
+  left: 3px;
+  position: absolute;
+  right: 3px;
+  top: 13px;
 }
 
 .gallery .edit-modal .range::-webkit-slider-thumb {
   -webkit-appearance: none;
   background-image: -webkit-image-set(
       url(../images/100/slider_thumb.png) 1x,
       url(../images/200/slider_thumb.png) 2x);
   height: 29px;
   width: 16px;
 }
@@ skipping 419 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;
 }