MD Settings: convert paper-icon-button to paper-icon-button-light.

chrome/browser/resources/settings/certificate_manager_page/certificate_subentry.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_action_menu/cr_action_menu.html">
 <link rel="import" href="chrome://resources/cr_elements/cr_lazy_render/cr_lazy_render.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.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-icon-button/paper-icon-button-light.html">
 <link rel="import" href="certificate_manager_types.html">
 <link rel="import" href="certificates_browser_proxy.html">
 <link rel="import" href="../settings_shared_css.html">
 
 <dom-module id="settings-certificate-subentry">
   <template>
     <style include="settings-shared">
       .name {
         flex: auto;
       }
 
       .untrusted {
         -webkit-margin-end: 16px;
         color: var(--settings-error-color);
         font-weight: 500;
         text-transform: uppercase;
       }
 
       :host([is-last]) .list-item {
         border-bottom: none;
       }
     </style>
     <div class="list-item underbar">
       <div class="untrusted" hidden$="[[!model.untrusted]]">
         $i18n{certificateManagerUntrusted}
       </div>
       <div class="name">[[model.name]]</div>
-      <paper-icon-button id="dots" icon="cr:more-vert"
-          title="$i18n{moreActions}" on-tap="onDotsTap_"></paper-icon-button>
+      <button is="paper-icon-button-light" class="icon-more-vert" id="dots"
+          title="$i18n{moreActions}" on-tap="onDotsTap_"></button>
       <template is="cr-lazy-render" id="menu">
         <dialog is="cr-action-menu">
           <button class="dropdown-item" role="option" id="view"
               on-tap="onViewTap_">
             $i18n{certificateManagerView}
           </button>
           <button class="dropdown-item" role="option" id="edit"
               hidden$="[[!canEdit_(certificateType, model)]]"
               on-tap="onEditTap_">
             $i18n{edit}
           </button>
           <button class="dropdown-item" role="option" id="export"
               hidden$="[[!canExport_(certificateType, model)]]"
               on-tap="onExportTap_">
             $i18n{certificateManagerExport}
           </button>
           <button class="dropdown-item" role="option" id="delete"
               hidden$="[[!canDelete_(model)]]" on-tap="onDeleteTap_">
             $i18n{certificateManagerDelete}
           </button>
         </dialog>
       </template>
     <div>
   </template>
   <script src="certificate_subentry.js"></script>
 </dom-module>