MD Settings: Fix <select> search highlighting.

chrome/browser/resources/settings/search_settings.js

 // 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.
 
 cr.define('settings', function() {
   /** @const {string} */
   var WRAPPER_CSS_CLASS = 'search-highlight-wrapper';
 
   /** @const {string} */
   var ORIGINAL_CONTENT_CSS_CLASS = 'search-highlight-original-content';
@@ skipping 131 matching lines @@
       }
 
       if (node.nodeType == Node.TEXT_NODE) {
         var textContent = node.nodeValue.trim();
         if (textContent.length == 0)
           return;
 
         if (request.regExp.test(textContent)) {
           foundMatches = true;
           revealParentSection_(node, request.rawQuery_);
-          highlight_(node, textContent.split(request.regExp));
+
+          // Don't highlight <select> nodes, yellow rectangles can't be
+          // displayed within an <option>.
+          // TODO(dpapad): highlight <select> controls with a search bubble
+          // instead.
+          if (node.parentNode.nodeName != 'OPTION')
+            highlight_(node, textContent.split(request.regExp));
         }
         // Returning early since TEXT_NODE nodes never have children.
         return;
       }
 
       var child = node.firstChild;
       while (child !== null) {
         // Getting a reference to the |nextSibling| before calling doSearch()
         // because |child| could be removed from the DOM within doSearch().
         var nextSibling = child.nextSibling;
@@ skipping 437 matching lines @@
   function setSearchManagerForTesting(searchManager) {
     SearchManagerImpl.instance_ = searchManager;
   }
 
   return {
     getSearchManager: getSearchManager,
     setSearchManagerForTesting: setSearchManagerForTesting,
     SearchRequest: SearchRequest,
   };
 });