Let guests on ChromeOS still search.

chrome/browser/resources/options/search_page.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.
 
 cr.define('options', function() {
   /** @const */ var Page = cr.ui.pageManager.Page;
   /** @const */ var PageManager = cr.ui.pageManager.PageManager;
 
   /**
    * Encapsulated handling of a search bubble.
    * @constructor
    */
   function SearchBubble(text) {
     var el = cr.doc.createElement('div');
     SearchBubble.decorate(el);
     el.content = text;
     return el;
   }
 
+  /**
+   * Prohibit search for guests on desktop.
+   */
+  function ShouldEnableSearch() {
+    return !loadTimeData.getBoolean('profileIsGuest') || cr.isChromeOS;
+  }
+
   SearchBubble.decorate = function(el) {
     el.__proto__ = SearchBubble.prototype;
     el.decorate();
   };
 
   SearchBubble.prototype = {
     __proto__: HTMLDivElement.prototype,
 
     decorate: function() {
       this.className = 'search-bubble';
@@ skipping 150 matching lines @@
      * Update the UI to reflect whether we are in a search state.
      * @param {boolean} active True if we are on the search page.
      * @private
      */
     setSearchActive_: function(active) {
       // It's fine to exit if search wasn't active and we're not going to
       // activate it now.
       if (!this.searchActive_ && !active)
         return;
 
-      // Guest users should never have active search.
-      if (loadTimeData.getBoolean('profileIsGuest'))
+      if (!ShouldEnableSearch())
         return;
 
       this.searchActive_ = active;
 
       if (active) {
         var hash = location.hash;
         if (hash) {
           this.searchField.value =
               decodeURIComponent(hash.slice(1).replace(/\+/g, ' '));
         } else if (!this.searchField.value) {
@@ skipping 55 matching lines @@
         }
       }
     },
 
     /**
      * Set the current search criteria.
      * @param {string} text Search text.
      * @private
      */
     setSearchText_: function(text) {
-      // Guest users should never have search text.
-      if (loadTimeData.getBoolean('profileIsGuest'))
+      if (!ShouldEnableSearch())
         return;
 
       // Prevent recursive execution of this method.
       if (this.insideSetSearchText_) return;
       this.insideSetSearchText_ = true;
 
       // Cleanup the search query string.
       text = SearchPage.canonicalizeQuery(text);
 
       // Set the hash on the current page, and the enclosing uber page. Only do
@@ skipping 297 matching lines @@
     // Trim beginning and ending whitespace.
     return text.replace(/^\s+|\s+$/g, '');
   };
 
   // Export
   return {
     SearchPage: SearchPage
   };
 
 });