[MD settings] replace secondary-action with separator

chrome/browser/resources/settings/internet_page/network_siminfo.html

 <link rel="import" href="chrome://resources/cr_elements/cr_dialog/cr_dialog.html">
 <link rel="import" href="chrome://resources/cr_elements/network/cr_onc_types.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-a11y-keys/iron-a11y-keys.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-input/paper-input.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-toggle-button/paper-toggle-button.html">
 <link rel="import" href="../icons.html">
 <link rel="import" href="internet_shared_css.html">
@@ skipping 48 matching lines @@
       </div>
     </div>
 
     <!-- SIM locked -->
     <div class="settings-box two-line"
         hidden$="[[!showSimLocked_(networkProperties)]]">
       <div class="start layout horizontal center">
         <iron-icon icon="settings:lock"></iron-icon>
         <div class="error">$i18n{networkSimCardLocked}</div>
       </div>
-      <div class="secondary-action">
-        <paper-button id="unlockPinButton" on-tap="onUnlockPinTap_">
-          $i18n{networkSimUnlock}
-        </paper-button>
-      </div>
+      <div class="separator"></div>
+      <paper-button id="unlockPinButton" on-tap="onUnlockPinTap_">
+        $i18n{networkSimUnlock}
+      </paper-button>
     </div>
 
     <!-- SIM unlocked -->
     <div class="settings-box two-line"
         hidden$="[[!showSimUnlocked_(networkProperties)]]">
       <div id="simLockToggleLabel" class="start">
         $i18n{networkSimLockEnable}
       </div>
       <paper-button id="changePinButton" on-tap="onChangePinTap_"
           hidden$="[[!networkProperties.Cellular.SIMLockStatus.LockEnabled]]">
@@ skipping 103 matching lines @@
       </div>
       <div class="button-container">
         <paper-button on-tap="sendUnlockPuk_">
           $i18n{networkSimUnlock}
         </paper-button>
       </div>
     </dialog>
   </template>
   <script src="network_siminfo.js"></script>
 </dom-module>