MD Settings: add "More actions..." text to all vertical 3-dot menus

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

 <link rel="import" href="chrome://resources/cr_elements/cr_action_menu/cr_action_menu.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="../extension_control_browser_proxy.html">
 <link rel="import" href="search_engine_entry_css.html">
 <link rel="import" href="../settings_shared_css.html">
 
 <dom-module id="settings-omnibox-extension-entry">
   <template>
     <style include="settings-shared search-engine-entry">
       .name-column {
         flex: 3;
       }
 
       .keyword-column {
         flex: 7;
       }
     </style>
     <div class="list-item">
       <div class="name-column">
         <span class="favicon-image"
             style="background-image: [[getIconSet_(engine.iconURL)]]"></span>
         <span class="name">[[engine.displayName]]</span>
       </div>
       <div class="keyword-column">[[engine.keyword]]</div>
       <paper-icon-button icon="cr:more-vert" tabindex$="[[tabindex]]"
-          on-tap="onDotsTap_">
+          on-tap="onDotsTap_" title="$i18n{moreActions}">
       </paper-icon-button>
       <dialog is="cr-action-menu">
         <button class="dropdown-item" role="option" on-tap="onManageTap_"
             id="manage">
           $i18n{searchEnginesManageExtension}
         </button>
         <button class="dropdown-item" role="option" on-tap="onDisableTap_"
             id="disable">
           $i18n{disable}
         </button>
       </dialog>
     </div>
   </template>
   <script src="omnibox_extension_entry.js"></script>
 </dom-module>