Pin keyboard works with virtual keyboard.

chrome/browser/resources/settings/people_page/setup_pin_dialog.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="/people_page/pin_keyboard.html">
 <link rel="import" href="/settings_shared_css.html">
 
 <dom-module id="settings-setup-pin-dialog">
   <template>
     <style include="settings-shared"></style>
     <style>
@@ skipping 28 matching lines @@
         <!-- Warning/error; only shown if title is hidden. -->
         <div class$="[[problemClass_]] settings-box first"
              hidden$="[[!hasProblem_(problemMessage_)]]">
           <iron-icon icon="icons:warning"></iron-icon>
           <span>[[problemMessage_]]</span>
         </div>
 
         <!-- Pin keyboard -->
         <div class="align-center settings-box continuation">
           <pin-keyboard id="pinKeyboard" on-pin-change="onPinChange_"
-                        on-submit="onPinSubmit_" value="{{pinKeyboardValue_}}">
+                        on-submit="onPinSubmit_" value="{{pinKeyboardValue_}}"
+                        enable-input-shown>

[jdufault, 2016/08/24 01:35:10]

rename to show-input?

[sammiequon, 2016/08/25 18:12:33]

Done.

           </pin-keyboard>
         </div>
 
         <div class="button-strip">
           <paper-button class="cancel-button" on-tap="onCancelTap_">
             $i18n{cancel}
           </paper-button>
 
           <paper-button class="action-button" on-tap="onPinSubmit_"
                         disabled$="[[!enableSubmit_]]">
             <span>[[getContinueMessage_(isConfirmStep_)]]</span>
           </paper-button>
         </div>
       </div>
     </dialog>
   </template>
 
   <script src="setup_pin_dialog.js"></script>
 </dom-module>