Enable PIN configuration settings.

chrome/app/chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ChromeOS-specific strings (included from generated_resources.grd).
      Everything in this file is wrapped in <if expr="chromeos">. -->
 <grit-part>
   <message name="IDS_EMPTY_STRING" desc="Empty string, exist only to make code generic. No translation required.">
   </message>
   <!-- Idle logout dialog for retail mode -->
   <message name="IDS_IDLE_LOGOUT_TITLE" desc="Dialog title for the idle logout dialog. Used in retail mode only.">
     Are you still there?
   </message>
@@ skipping 1368 matching lines @@
   </message>
   <message name="IDS_FLAGS_WAKE_ON_PACKETS_DESCRIPTION" desc="Description for the flag to enable wake on packets.">
     Enables waking the device based on the receipt of some network packets.
   </message>
   <message name="IDS_FLAGS_FULLSCREEN_APP_LIST_NAME" desc="Description for the flag to enable experimental fullscreen app list.">
     Enables the fullscreen app-list in touch-view mode.
   </message>
   <message name="IDS_FLAGS_FULLSCREEN_APP_LIST_DESCRIPTION" desc="Description for the flag to enable experimental fullscreen app list.">
     The app-list will appear as fullscreen mode when it's in touch view mode. This flag does nothing outside of the mode.
   </message>
+  <message name="IDS_FLAGS_QUICK_UNLOCK_PIN" desc="Title of the flag used to enable quick unlock pin.">
+    Quick Unlock (PIN)
+  </message>
+  <message name="IDS_FLAGS_QUICK_UNLOCK_PIN_DESCRIPTION" desc="Description of the flag used to enable quick unlock pin.">
+    Enabling PIN quick unlock allows you to use a PIN to unlock your Chromebook on the lock screen after you have signed into your device.
+  </message>
   <message name="IDS_FLAGS_STORAGE_MANAGER_NAME" desc="Description for the flag to enable experimental storage manager.">
     Storage manager
   </message>
   <message name="IDS_FLAGS_STORAGE_MANAGER_DESCRIPTION" desc="Description for the flag to enable experimental storage manager.">
     Enables storage manager to manage local storage.
   </message>
   <message name="IDS_OFFERS_CONSENT_INFOBAR_LABEL_LEARN_MORE" desc="Text of the Learn More link in the echo dialog.">
     Learn More
   </message>
   <message name="IDS_OFFERS_CONSENT_INFOBAR_ENABLE_BUTTON" desc="Enable button label.">
@@ skipping 5486 matching lines @@
   <message name="IDS_CRITICALLY_LOW_DISK_NOTIFICATION_TITLE" desc="Title of the notification warning users that they are critically low on disk space.">
     Device disk space critically low
   </message>
   <message name="IDS_CRITICALLY_LOW_DISK_NOTIFICATION_MESSAGE" desc="Notification text warning users that they are critically low on disk space.">
     Free up disk space or device will become unresponsive.
   </message>
   <message name="IDS_LOW_DISK_NOTIFICATION_BUTTON" desc="Button on the low disk notification to open storage management.">
     Manage storage
   </message>
 </grit-part>