Fixed UI stuck on Network screen after rebooting on FRE screen

BUG=432334
TEST=Manual test on Link

Review URL: https://codereview.chromium.org/740973002

Cr-Commit-Position: refs/heads/master@{#305003}

chrome/browser/ui/webui/chromeos/login/enrollment_screen_handler.cc

@@ -20,6 +20,7 @@
 #include "chrome/browser/chromeos/login/error_screens_histogram_helper.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host_impl.h"
 #include "chrome/browser/chromeos/policy/policy_oauth2_token_fetcher.h"
+#include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/extensions/signin/gaia_auth_extension_loader.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/chromeos/login/oobe_ui.h"
@@ -117,6 +118,7 @@ EnrollmentScreenHandler::EnrollmentScreenHandler(
       network_state_informer_(network_state_informer),
       error_screen_actor_(error_screen_actor),
       histogram_helper_(new ErrorScreensHistogramHelper("Enrollment")),
+      auth_extension_(nullptr),
       weak_ptr_factory_(this) {
   set_async_assets_load_id(OobeUI::kScreenOobeEnrollment);
   DCHECK(network_state_informer_.get());
@@ -173,6 +175,11 @@ void EnrollmentScreenHandler::PrepareToShow() {
 }
 
 void EnrollmentScreenHandler::Show() {
+  if (!auth_extension_) {
+    Profile* signin_profile = ProfileHelper::GetSigninProfile();
+    auth_extension_.reset(new ScopedGaiaAuthExtension(signin_profile));
+  }
+
   if (!page_is_ready())
     show_on_init_ = true;
   else

chrome/browser/ui/webui/chromeos/login/enrollment_screen_handler.h

@@ -15,6 +15,7 @@
 #include "chrome/browser/browsing_data/browsing_data_remover.h"
 #include "chrome/browser/chromeos/login/enrollment/enrollment_screen_actor.h"
 #include "chrome/browser/chromeos/login/ui/webui_login_view.h"
+#include "chrome/browser/extensions/signin/scoped_gaia_auth_extension.h"
 #include "chrome/browser/ui/webui/chromeos/login/base_screen_handler.h"
 #include "chrome/browser/ui/webui/chromeos/login/network_state_informer.h"
 
@@ -148,6 +149,9 @@ class EnrollmentScreenHandler
 
   scoped_ptr<ErrorScreensHistogramHelper> histogram_helper_;
 
+  // GAIA extension loader.
+  scoped_ptr<ScopedGaiaAuthExtension> auth_extension_;
+
   base::WeakPtrFactory<EnrollmentScreenHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(EnrollmentScreenHandler);