MD Settings: make custom UIs look "actionable"

chrome/browser/resources/settings/site_settings/site_list.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/web_ui_listener_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-icon/iron-icon.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-menu/paper-menu.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-menu/paper-submenu.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-menu-button/paper-menu-button.html">
 <link rel="import" href="/i18n_setup.html">
@@ skipping 17 matching lines @@
       .button-container {
         -webkit-margin-start: -4px;
       }
 
       .no-upper {
         text-transform: none;
       }
     </style>
     <paper-submenu id="category" hidden
         on-paper-submenu-open="onToggle_" on-paper-submenu-close="onToggle_">
-      <div class="menu-trigger settings-box" hidden$="[[allSites]]">
+      <div class="menu-trigger settings-box" hidden$="[[allSites]]" actionable>
         <div class="flex" id="header">
           [[computeSiteListHeader_(sites, categoryEnabled)]]
         </div>
         <iron-icon id="icon" icon="cr:expand-more"></iron-icon>
       </div>
 
       <div class="list-frame menu-content vertical-list" id="listContainer">
         <template is="dom-repeat" items="[[sites]]">
           <div class="list-item underscore">
             <div class="favicon-image" style$="[[computeSiteIcon(item)]]"
-                on-tap="onOriginTap_"></div>
-            <div class="middle" on-tap="onOriginTap_">
+                on-tap="onOriginTap_" actionable></div>
+            <div class="middle" on-tap="onOriginTap_" actionable>
               <div>[[item.originForDisplay]]</div>
               <div class="secondary">[[item.embeddingOriginForDisplay]]</div>
             </div>
             <paper-menu-button hidden$="[[allSites]]">
               <paper-icon-button icon="cr:more-vert"
                   class="dropdown-trigger">
               </paper-icon-button>
               <paper-menu id="actionMenu" class="dropdown-content"
                   on-iron-activate="onActionMenuIronActivate_"
                   attr-for-selected="menu-value">
@@ skipping 24 matching lines @@
         <div class="button-container">
           <paper-button on-tap="onAddSiteTap_" class="primary-button no-upper">
             $i18n{addSiteLink}
           </paper-button>
         </div>
       </div>
     </paper-submenu>
   </template>
   <script src="site_list.js"></script>
 </dom-module>