MD Settings: omnibox extensions list to use focus-row-behavior.

chrome/browser/resources/settings/search_engines_page/search_engines_page.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/action_link.html">
 <link rel="import" href="chrome://resources/html/action_link_css.html">
 <link rel="import" href="chrome://resources/html/cr.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="search_engines_browser_proxy.html">
 <link rel="import" href="search_engine_dialog.html">
 <link rel="import" href="search_engines_list.html">
 <link rel="import" href="omnibox_extension_entry.html">
 <link rel="import" href="../global_scroll_target_behavior.html">
@@ skipping 31 matching lines @@
       $i18n{searchEnginesNoOtherEngines}
     </div>
     <settings-search-engines-list id="otherEngines" engines="[[otherEngines]]"
           hide-headers scroll-target="[[subpageScrollTarget]]">
     </settings-search-engines-list>
     <template is="dom-if" if="[[showExtensionsList_]]">
       <div class="settings-box first">
         <h2>$i18n{searchEnginesExtension}</h2>
       </div>
       <iron-list id="extensions" class="extension-engines fixed-height-list"
-          selectable items="[[extensions]]">
+          items="[[extensions]]">
         <template>
           <settings-omnibox-extension-entry engine="[[item]]"
-              tabindex$="[[tabIndex]]">
+              tabindex$="[[tabIndex]]" iron-list-tab-index="[[tabIndex]]"

[hcarmona, 2017/05/04 21:03:35]

do you need both tabindex and iron-list-tab-index?

[scottchen, 2017/05/04 21:57:38]

yeah, the js code uses them to do slightly different things.

[hcarmona, 2017/05/04 22:51:35]

SG

+              last-focused="{{OmniboxExtensionlastFocused_}}">
           </settings-omnibox-extension-entry>
         </template>
       </iron-list>
     </template>
   </template>
   <script src="search_engines_page.js"></script>
 </dom-module>