Disable wallpaper button in Guest mode settings

ui/webui/resources/js/chromeos/ui_account_tweaks.js

 // 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.
 
 /**
  * @fileoverview This file contains methods that allow to tweak
  * internal page UI based on the status of current user (owner/user/guest).
  * It is assumed that required data is passed via i18n strings
  * (using loadTimeData dictionary) that are filled with call to
  * AddAccountUITweaksLocalizedValues in ui_account_tweaks.cc.
@@ skipping 39 matching lines @@
   };
 
   /**
    * @return {boolean} Whether we're currently in supervised user mode.
    */
   UIAccountTweaks.loggedInAsSupervisedUser = function() {
     return loadTimeData.getBoolean('loggedInAsSupervisedUser');
   };
 
   /**
+   * Enables an element unless it should be disabled for the session type.
+   *
+   * @param {!Element} element Element that should be enabled.
+   */
+  UIAccountTweaks.enableElementIfPossible = function(element) {
+    var sessionType;
+    if (UIAccountTweaks.loggedInAsGuest())
+      sessionType = SESSION_TYPE_GUEST;
+    else if (UIAccountTweaks.loggedInAsPublicAccount())
+      sessionType = SESSION_TYPE_PUBLIC;
+
+    if (sessionType &&
+        element.getAttribute(sessionType + '-visibility') == 'disabled') {
+      return;
+    }
+
+    element.disabled = false;
+  }
+
+  /**
    * Disables or hides some elements in specified type of session in ChromeOS.
    * All elements within given document with *sessionType*-visibility
    * attribute are either hidden (for *sessionType*-visibility="hidden")
    * or disabled (for *sessionType*-visibility="disabled").
    *
    * @param {Document} document Document that should processed.
    * @param {string} sessionType name of the session type processed.
    * @private
    */
   UIAccountTweaks.applySessionTypeVisibility_ = function(document,
                                                          sessionType) {
-    var elements = document.querySelectorAll('['+ sessionType +'-visibility]');
+    var elements = document.querySelectorAll('['+ sessionType + '-visibility]');
     for (var i = 0; i < elements.length; i++) {
       var element = elements[i];
-      var visibility = element.getAttribute(sessionType +'-visibility');
+      var visibility = element.getAttribute(sessionType + '-visibility');
       if (visibility == 'hidden')
         element.hidden = true;
       else if (visibility == 'disabled')
         UIAccountTweaks.disableElementsForSessionType(element, sessionType);
     }
   }
 
   /**
    * Updates specific visibility of elements for Guest session in ChromeOS.
    * Calls applySessionTypeVisibility_ method.
    *
    * @param {Document} document Document that should processed.
    */
   UIAccountTweaks.applyGuestSessionVisibility = function(document) {
-    if (!cr.isChromeOS || !UIAccountTweaks.loggedInAsGuest())
+    if (!UIAccountTweaks.loggedInAsGuest())
       return;
     UIAccountTweaks.applySessionTypeVisibility_(document, SESSION_TYPE_GUEST);
   }
 
   /**
    * Updates specific visibility of elements for Public account session in
    * ChromeOS. Calls applySessionTypeVisibility_ method.
    *
    * @param {Document} document Document that should processed.
    */
   UIAccountTweaks.applyPublicSessionVisibility = function(document) {
-    if (!cr.isChromeOS || !UIAccountTweaks.loggedInAsPublicAccount())
+    if (!UIAccountTweaks.loggedInAsPublicAccount())
       return;
     UIAccountTweaks.applySessionTypeVisibility_(document, SESSION_TYPE_PUBLIC);
   }
 
   /**
    * Disables and marks page elements for specified session type.
    * Adds #-disabled css class to all elements within given subtree,
    * disables interactive elements (input/select/button), and removes href
    * attribute from <a> elements.
    *
@@ skipping 42 matching lines @@
       };
     }
   };
 
   // Export
   return {
     UIAccountTweaks: UIAccountTweaks
   };
 
 });