Enable bootstrapping feature by default.

chrome/browser/chromeos/login/existing_user_controller_browsertest.cc

Index: chrome/browser/chromeos/login/existing_user_controller_browsertest.cc
diff --git a/chrome/browser/chromeos/login/existing_user_controller_browsertest.cc b/chrome/browser/chromeos/login/existing_user_controller_browsertest.cc
index 1fb92a8fd1bf1c7debaaad11e8e8a0ec577c8af3..d72953d48a68ae3074c3e45f1a283d8fc6aa5b8e 100644
--- a/chrome/browser/chromeos/login/existing_user_controller_browsertest.cc
+++ b/chrome/browser/chromeos/login/existing_user_controller_browsertest.cc
@@ -415,6 +415,10 @@ class ExistingUserControllerPublicSessionTest
     WizardController* controller = WizardController::default_controller();
     if (controller && controller->current_screen())
       controller->current_screen()->Hide();
+
+    if (LoginDisplayHost::default_host())
+      LoginDisplayHost::default_host()->Finalize();
+    base::MessageLoop::current()->RunUntilIdle();
   }
 
   void ExpectSuccessfulLogin(const UserContext& user_context) {