MD History: Add tooltip to more actions button in synced tabs

chrome/browser/resources/md_history/synced_device_card.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/polymer/v1_0/iron-collapse/iron-collapse.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="chrome://resources/html/icon.html">
 <link rel="import" href="chrome://history/browser_service.html">
 <link rel="import" href="chrome://history/constants.html">
 <link rel="import" href="chrome://history/searched_label.html">
@@ skipping 58 matching lines @@
     </style>
     <div id="history-item-container">
       <div class="card-title" id="card-heading" aria-expanded$="[[cardOpen_]]"
           aria-controls="collapse" on-tap="toggleTabCard">
         <div>
           [[device]]
           <span id="last-update-time">[[lastUpdateTime]]</span>
         </div>
         <div id="right-buttons">
           <button is="paper-icon-button-light" id="menu-button"
-              class="icon-button" on-tap="onMenuButtonTap_">
+              class="icon-button" on-tap="onMenuButtonTap_"
+              title="$i18n{moreActionsButton}">
             <iron-icon icon="cr:more-vert"></iron-icon>
           </button>
           <button is="paper-icon-button-light" class="icon-button"
               title$="[[getCollapseTitle_(cardOpen_)]]">
             <iron-icon icon="cr:expand-less" id="dropdown-indicator">
             </iron-icon>
           </button>
         </div>
       </div>
 
@@ skipping 11 matching lines @@
             <div id="window-separator"
                 hidden$="[[!isWindowSeparatorIndex_(index, separatorIndexes)]]">
             </div>
           </template>
         </div>
       </iron-collapse>
     </div>
   </template>
   <script src="chrome://history/synced_device_card.js"></script>
 </dom-module>