[MD settings] list-button class shows actionable style mouse

chrome/browser/resources/settings/settings_shared_css.html

 <link rel="import" href="chrome://resources/cr_elements/shared_style_css.html">
 <link rel="import" href="/settings_vars_css.html">
 
 <!-- Common styles for Material Design settings. -->
 <dom-module id="settings-shared">
   <template>
     <style include="cr-shared-style">
       h2 {
         align-items: center;
         display: flex;
@@ skipping 216 matching lines @@
       .list-item > label span[disabled] {
         opacity: .65;  /* TODO(michaelpg): check this value with bettes. */
       }
 
       .list-item > paper-icon-item {
         padding: 0;
       }
 
       /* This button has no ink ripple. */
       .list-item.list-button {
+        @apply(--settings-actionable);
         align-items: center;
         color: var(--google-blue-500);
         font-weight: 500;
       }
 
       /* A settings-box is a horizontal row of text or controls within a
        * setting section (page or subpage). */
       .settings-box {
         align-items: center;
         border-top: var(--settings-separator-line);
@@ skipping 115 matching lines @@
         content: '';
         height: 10px;
         position: absolute;
         right: -5px;
         top: 10px;
         width: 10px;
       }
     </style>
   </template>
 </dom-module>