[MD settings] show icon when slider controlled by something

chrome/browser/resources/settings/device_page/compiled_resources2.gyp

 # Copyright 2016 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.
 {
   'targets': [
     {
       'target_name': 'device_page',
       'dependencies': [
         '../compiled_resources2.gyp:route',
         '<(DEPTH)/ui/webui/resources/js/compiled_resources2.gyp:i18n_behavior',
@@ skipping 37 matching lines @@
         '../prefs/compiled_resources2.gyp:prefs_types',
         'device_page_browser_proxy'
       ],
       'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
     {
       'target_name': 'display',
       'dependencies': [
         '<(DEPTH)/ui/webui/resources/js/compiled_resources2.gyp:cr',
         '<(DEPTH)/ui/webui/resources/js/compiled_resources2.gyp:i18n_behavior',
+        '<(EXTERNS_GYP):settings_private',
         '<(EXTERNS_GYP):system_display',
         '<(INTERFACES_GYP):system_display_interface',
         'display_layout'
       ],
       'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
     {
       'target_name': 'display_layout',
       'dependencies': [
         '<(DEPTH)/third_party/polymer/v1_0/components-chromium/iron-resizable-behavior/compiled_resources2.gyp:iron-resizable-behavior-extracted',
@@ skipping 54 matching lines @@
     {
       'target_name': 'drive_cache_dialog',
       'dependencies': [
         '<(DEPTH)/ui/webui/resources/js/compiled_resources2.gyp:i18n_behavior',
         '<(EXTERNS_GYP):chrome_send',
       ],
       'includes': ['../../../../../third_party/closure_compiler/compile_js2.gypi'],
     },
  ],
 }