Enable login screen apps.

chrome/browser/extensions/extension_system_impl.cc

Index: chrome/browser/extensions/extension_system_impl.cc
diff --git a/chrome/browser/extensions/extension_system_impl.cc b/chrome/browser/extensions/extension_system_impl.cc
index fa7596f5ad8971e9170674d058eb884391aea2e6..962e17fe0dc8af2b1f794c6b10468fb8954a2969 100644
--- a/chrome/browser/extensions/extension_system_impl.cc
+++ b/chrome/browser/extensions/extension_system_impl.cc
@@ -67,6 +67,7 @@
 #include "chrome/browser/chromeos/app_mode/kiosk_app_update_install_gate.h"
 #include "chrome/browser/chromeos/extensions/device_local_account_management_policy_provider.h"
 #include "chrome/browser/chromeos/policy/device_local_account.h"
+#include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chromeos/chromeos_switches.h"
 #include "chromeos/login/login_state.h"
 #include "components/user_manager/user.h"
@@ -189,6 +190,11 @@ void ExtensionSystemImpl::Shared::Init(bool extensions_enabled) {
   bool autoupdate_enabled = !profile_->IsGuestSession() &&
                             !profile_->IsSystemProfile();
 #if defined(OS_CHROMEOS)
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableLoginApps) &&
+      chromeos::ProfileHelper::IsSigninProfile(profile_)) {
+    extensions_enabled = true;
+  }
   if (!extensions_enabled)
     autoupdate_enabled = false;
 #endif  // defined(OS_CHROMEOS)