Add stub icons for playpen.

chrome/browser/resources/chromeos/login/user_pod_row.css

Index: chrome/browser/resources/chromeos/login/user_pod_row.css
diff --git a/chrome/browser/resources/chromeos/login/user_pod_row.css b/chrome/browser/resources/chromeos/login/user_pod_row.css
index e8d2e656672fa48a0e09c222c2ebc7155a4d3207..4d3cac92a27bc0b9a0abf2c0c20eb8223bbc40ee 100644
--- a/chrome/browser/resources/chromeos/login/user_pod_row.css
+++ b/chrome/browser/resources/chromeos/login/user_pod_row.css
@@ -222,7 +222,7 @@ html[dir=rtl] .pod .capslock-hint {
 
 .user-type-icon-image {
   background-color: transparent;
-  background-image: url('chrome://theme/IDR_OOBE_ACTION_BOX_BUTTON_NORMAL');
+  background-image: url('chrome://theme/IDR_MANAGED_MODE_ICON');
   border: 0 !important;
   height: 16px;
   margin: 5px;
@@ -230,7 +230,6 @@ html[dir=rtl] .pod .capslock-hint {
   width: 16px;
 }
 
-
 html[dir=rtl] .action-box-area {
   left: 0;
   right: auto;