Revert "cros oobe: Make Gaia screen a part of wizard controller screens"

This reverts commit 9bc4b728.

Reason for revert: Suspected cause for ChromeSessionManagerTest.OobeNewUser flakiness. see
BUG=1110996

Original change's description:
> cros oobe: Make Gaia screen a part of wizard controller screens
> 
> This CL modifies code in a way that GaiaScreenHandler is owned and
> handled by GaiaScreen.
> 
> TBR=alemate@chromium.org
> 
> Bug: 1079199
> Change-Id: Idea2f8b9a2974007286e9e8562d1bcee0f2df423
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2279800
> Commit-Queue: Roman Sorokin [CET] <rsorokin@chromium.org>
> Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#792674}

TBR=antrim@chromium.org,alemate@chromium.org,rsorokin@chromium.org

Change-Id: I7e677d7b35b414b3ef18023a8fc4052c25fec3cf
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1079199
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2327314Reviewed-by: Toni Baržić <tbarzic@chromium.org>
Commit-Queue: Toni Baržić <tbarzic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792817}

chrome/browser/chromeos/login/screens/gaia_screen.cc

@@ -4,39 +4,12 @@
 
 #include "chrome/browser/chromeos/login/screens/gaia_screen.h"
 
-#include "chrome/browser/chromeos/login/screen_manager.h"
 #include "chrome/browser/ui/webui/chromeos/login/gaia_screen_handler.h"
-#include "components/account_id/account_id.h"
 
 namespace chromeos {
 
-GaiaScreen::GaiaScreen()
-    : BaseScreen(GaiaView::kScreenId, OobeScreenPriority::DEFAULT) {}
-
-// static
-GaiaScreen* GaiaScreen::Get(ScreenManager* manager) {
-  return static_cast<GaiaScreen*>(manager->GetScreen(GaiaView::kScreenId));
-}
-
 void GaiaScreen::MaybePreloadAuthExtension() {
   view_->MaybePreloadAuthExtension();
 }
 
-void GaiaScreen::LoadOnline(const AccountId& account) {
-  view_->LoadGaiaAsync(account);
-}
-
-void GaiaScreen::LoadOffline(const AccountId& account) {
-  view_->LoadOfflineGaia(account);
-}
-
-void GaiaScreen::ShowImpl() {
-  view_->Show();
-}
-
-void GaiaScreen::HideImpl() {
-  view_->LoadGaiaAsync(EmptyAccountId());
-  view_->Hide();
-}
-
 }  // namespace chromeos

chrome/browser/chromeos/login/screens/gaia_screen.h

@@ -8,35 +8,25 @@
 #include <string>
 
 #include "base/bind.h"
+#include "base/compiler_specific.h"
 #include "base/macros.h"
-#include "chrome/browser/chromeos/login/screens/base_screen.h"
 
 namespace chromeos {
 
 class GaiaView;
-class ScreenManager;
 
 // This class represents GAIA screen: login screen that is responsible for
 // GAIA-based sign-in.
-class GaiaScreen : public BaseScreen {
+class GaiaScreen {
  public:
-  GaiaScreen();
-  ~GaiaScreen() override = default;
-
-  static GaiaScreen* Get(ScreenManager* manager);
+  GaiaScreen() = default;
+  virtual ~GaiaScreen() = default;
 
   void set_view(GaiaView* view) { view_ = view; }
 
   void MaybePreloadAuthExtension();
-  // Loads online Gaia into the webview.
-  void LoadOnline(const AccountId& account);
-  // Loads offline version of Gaia.
-  void LoadOffline(const AccountId& account);
 
  private:
-  void ShowImpl() override;
-  void HideImpl() override;
-
   GaiaView* view_ = nullptr;
 
   DISALLOW_COPY_AND_ASSIGN(GaiaScreen);

chrome/browser/chromeos/login/screens/update_required_screen.cc

@@ -50,13 +50,11 @@ UpdateRequiredScreen* UpdateRequiredScreen::Get(ScreenManager* manager) {
 }
 
 UpdateRequiredScreen::UpdateRequiredScreen(UpdateRequiredView* view,
-                                           ErrorScreen* error_screen,
-                                           base::RepeatingClosure exit_callback)
+                                           ErrorScreen* error_screen)
     : BaseScreen(UpdateRequiredView::kScreenId,
                  OobeScreenPriority::SCREEN_UPDATE_REQUIRED),
       view_(view),
       error_screen_(error_screen),
-      exit_callback_(std::move(exit_callback)),
       histogram_helper_(
           std::make_unique<ErrorScreensHistogramHelper>("UpdateRequired")),
       version_updater_(std::make_unique<VersionUpdater>(this)),
@@ -378,11 +376,6 @@ void UpdateRequiredScreen::FinishExitUpdate(VersionUpdater::Result result) {
     view_->SetUIState(UpdateRequiredView::UPDATE_ERROR);
 }
 
-void UpdateRequiredScreen::Exit() {
-  DCHECK(!is_hidden());
-  exit_callback_.Run();
-}
-
 VersionUpdater* UpdateRequiredScreen::GetVersionUpdaterForTesting() {
   return version_updater_.get();
 }

chrome/browser/chromeos/login/screens/update_required_screen.h

@@ -35,9 +35,7 @@ class UpdateRequiredScreen : public BaseScreen,
  public:
   static UpdateRequiredScreen* Get(ScreenManager* manager);
 
-  UpdateRequiredScreen(UpdateRequiredView* view,
-                       ErrorScreen* error_screen,
-                       base::RepeatingClosure exit_callback);
+  UpdateRequiredScreen(UpdateRequiredView* view, ErrorScreen* error_screen);
   ~UpdateRequiredScreen() override;
 
   // Called when the being destroyed. This should call Unbind() on the
@@ -57,9 +55,6 @@ class UpdateRequiredScreen : public BaseScreen,
       const VersionUpdater::UpdateInfo& update_info) override;
   void FinishExitUpdate(VersionUpdater::Result result) override;
 
-  // Exit the screen.
-  void Exit();
-
   VersionUpdater* GetVersionUpdaterForTesting();
 
   // Set a base clock (used to set current time) for testing EOL.
@@ -108,7 +103,6 @@ class UpdateRequiredScreen : public BaseScreen,
 
   UpdateRequiredView* view_ = nullptr;
   ErrorScreen* error_screen_;
-  base::RepeatingClosure exit_callback_;
   std::unique_ptr<ErrorScreensHistogramHelper> histogram_helper_;
 
   // Whether the screen is shown.

chrome/browser/chromeos/login/screens/update_required_screen_unittest.cc

@@ -71,7 +71,7 @@ class UpdateRequiredScreenUnitTest : public testing::Test {
         .WillRepeatedly(Return(false));
 
     update_required_screen_ = std::make_unique<UpdateRequiredScreen>(
-        fake_view_.get(), mock_error_screen_.get(), base::DoNothing());
+        fake_view_.get(), mock_error_screen_.get());
 
     update_required_screen_->GetVersionUpdaterForTesting()
         ->set_wait_for_reboot_time_for_testing(base::TimeDelta::FromSeconds(0));

chrome/browser/chromeos/login/test/oobe_screen_exit_waiter.cc

@@ -7,7 +7,6 @@
 #include "base/logging.h"
 #include "base/run_loop.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host.h"
-#include "testing/gtest/include/gtest/gtest.h"
 
 namespace chromeos {
 
@@ -36,7 +35,7 @@ void OobeScreenExitWaiter::Wait() {
   run_loop_->Run();
   run_loop_.reset();
 
-  ASSERT_EQ(State::DONE, state_);
+  DCHECK_EQ(State::DONE, state_);
 
   oobe_ui_observer_.RemoveAll();
 }

chrome/browser/chromeos/login/ui/login_display_host_common.cc

@@ -13,7 +13,6 @@
 #include "chrome/browser/chromeos/login/demo_mode/demo_app_launcher.h"
 #include "chrome/browser/chromeos/login/existing_user_controller.h"
 #include "chrome/browser/chromeos/login/kiosk_launch_controller.h"
-#include "chrome/browser/chromeos/login/screens/gaia_screen.h"
 #include "chrome/browser/chromeos/login/startup_utils.h"
 #include "chrome/browser/chromeos/login/ui/webui_accelerator_mapping.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
@@ -118,6 +117,11 @@ void LoginDisplayHostCommon::StartSignInScreen() {
   connector->ScheduleServiceInitialization(
       kPolicyServiceInitializationDelayMilliseconds);
 
+  // Inform wizard controller that login screen has started.
+  // TODO(crbug.com/1064271): Move this to OnStartSignInScreen().
+  if (WizardController::default_controller())
+    WizardController::default_controller()->LoginScreenStarted();
+
   // Run UI-specific logic.
   OnStartSignInScreen();
 
@@ -305,22 +309,23 @@ void LoginDisplayHostCommon::OnStartSignInScreenCommon() {
 
 void LoginDisplayHostCommon::ShowGaiaDialogCommon(
     const AccountId& prefilled_account) {
+  DCHECK(GetOobeUI());
+
   if (prefilled_account.is_valid()) {
-    LoadWallpaper(prefilled_account);
-    if (GetLoginDisplay()->delegate()->IsSigninInProgress()) {
-      return;
+    // Make sure gaia displays |account| if requested.
+    if (!GetLoginDisplay()->delegate()->IsSigninInProgress()) {
+      GetOobeUI()->GetView<GaiaScreenHandler>()->ShowGaiaAsync(
+          prefilled_account);
     }
+    LoadWallpaper(prefilled_account);
   } else {
+    if (GetOobeUI()->current_screen() != GaiaView::kScreenId) {
+      GetOobeUI()->GetView<GaiaScreenHandler>()->ShowGaiaAsync(
+          EmptyAccountId());
+    }
     LoadSigninWallpaper();
   }
-
-  DCHECK(GetWizardController());
-  GaiaScreen* gaia_screen =
-      GaiaScreen::Get(GetWizardController()->screen_manager());
-  gaia_screen->LoadOnline(prefilled_account);
-  StartWizard(GaiaView::kScreenId);
 }
-
 void LoginDisplayHostCommon::Cleanup() {
   ProfileHelper::Get()->ClearSigninProfile(base::DoNothing());
   registrar_.RemoveAll();

chrome/browser/chromeos/login/ui/login_display_host_mojo.cc

@@ -22,7 +22,6 @@
 #include "chrome/browser/chromeos/login/mojo_system_info_dispatcher.h"
 #include "chrome/browser/chromeos/login/reauth_stats.h"
 #include "chrome/browser/chromeos/login/screens/chrome_user_selection_screen.h"
-#include "chrome/browser/chromeos/login/screens/gaia_screen.h"
 #include "chrome/browser/chromeos/login/ui/login_display.h"
 #include "chrome/browser/chromeos/login/ui/login_display_mojo.h"
 #include "chrome/browser/chromeos/login/user_board_view_mojo.h"
@@ -119,9 +118,7 @@ void LoginDisplayHostMojo::SetUserCount(int user_count) {
   // And if the dialog shows login screen.
   if (was_zero_users && user_count_ != 0 && dialog_ && dialog_->IsVisible() &&
       (!wizard_controller_->is_initialized() ||
-       (wizard_controller_->current_screen() &&
-        wizard_controller_->current_screen()->screen_id() ==
-            GaiaView::kScreenId))) {
+       wizard_controller_->login_screen_started())) {
     HideOobeDialog();
   }
 }
@@ -256,21 +253,8 @@ void LoginDisplayHostMojo::OnStartSignInScreen() {
   if (signin_screen_started_) {
     // If we already have a signin screen instance, just reset the state of the
     // oobe dialog.
-
-    // Try to switch to Gaia screen.
-    StartWizard(GaiaView::kScreenId);
-
-    if (wizard_controller_->current_screen() &&
-        wizard_controller_->current_screen()->screen_id() !=
-            GaiaView::kScreenId) {
-      // Switching might fail due to the screen priorities. Do no hide the
-      // dialog in that case.
-      return;
-    }
-
-    // Maybe hide dialog if there are existing users. It also reloads Gaia.
     HideOobeDialog();
-
+    GetOobeUI()->GetView<GaiaScreenHandler>()->ShowGaiaAsync(EmptyAccountId());
     return;
   }
 
@@ -334,9 +318,7 @@ void LoginDisplayHostMojo::HideOobeDialog() {
   const bool no_users =
       !login_display_->IsSigninInProgress() && user_count_ == 0;
   if (no_users || GetOobeUI()->current_screen() == GaiaView::kScreenId) {
-    GaiaScreen* gaia_screen =
-        GaiaScreen::Get(GetWizardController()->screen_manager());
-    gaia_screen->LoadOnline(EmptyAccountId());
+    GetOobeUI()->GetView<GaiaScreenHandler>()->ShowGaiaAsync(EmptyAccountId());
     if (no_users)
       return;
   }

chrome/browser/chromeos/login/ui/login_display_host_webui.cc

@@ -573,7 +573,7 @@ void LoginDisplayHostWebUI::StartWizard(OobeScreenId first_screen) {
   // Keep parameters to restore if renderer crashes.
   restore_path_ = RESTORE_WIZARD;
   first_screen_ = first_screen;
-  is_showing_login_ = (first_screen == GaiaView::kScreenId);
+  is_showing_login_ = false;
 
   VLOG(1) << "Login WebUI >> wizard";
 

chrome/browser/chromeos/login/wizard_controller.cc

@@ -66,7 +66,6 @@
 #include "chrome/browser/chromeos/login/screens/family_link_notice_screen.h"
 #include "chrome/browser/chromeos/login/screens/fingerprint_setup_screen.h"
 #include "chrome/browser/chromeos/login/screens/gaia_password_changed_screen.h"
-#include "chrome/browser/chromeos/login/screens/gaia_screen.h"
 #include "chrome/browser/chromeos/login/screens/gesture_navigation_screen.h"
 #include "chrome/browser/chromeos/login/screens/hid_detection_screen.h"
 #include "chrome/browser/chromeos/login/screens/kiosk_autolaunch_screen.h"
@@ -566,9 +565,7 @@ std::vector<std::unique_ptr<BaseScreen>> WizardController::CreateScreens() {
                           weak_factory_.GetWeakPtr())));
   append(std::make_unique<UpdateRequiredScreen>(
       oobe_ui->GetView<UpdateRequiredScreenHandler>(),
-      oobe_ui->GetErrorScreen(),
-      base::BindRepeating(&WizardController::OnUpdateRequiredScreenExit,
-                          weak_factory_.GetWeakPtr())));
+      oobe_ui->GetErrorScreen()));
   append(std::make_unique<AssistantOptInFlowScreen>(
       oobe_ui->GetView<AssistantOptInFlowScreenHandler>(),
       base::BindRepeating(&WizardController::OnAssistantOptInFlowScreenExit,
@@ -597,9 +594,6 @@ std::vector<std::unique_ptr<BaseScreen>> WizardController::CreateScreens() {
       oobe_ui->GetView<PackagedLicenseScreenHandler>(),
       base::BindRepeating(&WizardController::OnPackagedLicenseScreenExit,
                           weak_factory_.GetWeakPtr())));
-  auto gaia_screen = std::make_unique<GaiaScreen>();
-  gaia_screen->set_view(oobe_ui->GetView<GaiaScreenHandler>());
-  append(std::move(gaia_screen));
 
   append(std::make_unique<TpmErrorScreen>(
       oobe_ui->GetView<TpmErrorScreenHandler>()));
@@ -637,6 +631,10 @@ void WizardController::OnOwnershipStatusCheckDone(
     ShowLoginScreen();
 }
 
+void WizardController::LoginScreenStarted() {
+  SetCurrentScreen(nullptr);
+}
+
 void WizardController::ShowLoginScreen() {
   // This may be triggered by multiply asynchronous events from the JS side.
   if (login_screen_started_)
@@ -1291,17 +1289,11 @@ void WizardController::OnChangedMetricsReportingState(bool enabled) {
 }
 
 void WizardController::OnDeviceModificationCanceled() {
-  current_screen_->Hide();
-  current_screen_ = nullptr;
   if (previous_screen_) {
-    if (previous_screen_ == GetScreen(GaiaView::kScreenId)) {
-      ShowLoginScreen();
-    } else {
-      SetCurrentScreen(previous_screen_);
-    }
-    return;
+    SetCurrentScreen(previous_screen_);
+  } else {
+    ShowPackagedLicenseScreen();
   }
-  ShowPackagedLicenseScreen();
 }
 
 void WizardController::OnSupervisionTransitionScreenExit() {
@@ -1310,12 +1302,6 @@ void WizardController::OnSupervisionTransitionScreenExit() {
   OnOobeFlowFinished();
 }
 
-void WizardController::OnUpdateRequiredScreenExit() {
-  current_screen_->Hide();
-  current_screen_ = nullptr;
-  ShowLoginScreen();
-}
-
 void WizardController::OnPackagedLicenseScreenExit(
     PackagedLicenseScreen::Result result) {
   OnScreenExit(PackagedLicenseView::kScreenId,
@@ -1636,8 +1622,7 @@ void WizardController::AdvanceToScreen(OobeScreenId screen_id) {
   } else if (screen_id == TpmErrorView::kScreenId ||
              screen_id == GaiaPasswordChangedView::kScreenId ||
              screen_id == ActiveDirectoryPasswordChangeView::kScreenId ||
-             screen_id == FamilyLinkNoticeView::kScreenId ||
-             screen_id == GaiaView::kScreenId) {
+             screen_id == FamilyLinkNoticeView::kScreenId) {
     SetCurrentScreen(GetScreen(screen_id));
   } else {
     if (is_out_of_box_) {

chrome/browser/chromeos/login/wizard_controller.h

@@ -173,6 +173,9 @@ class WizardController {
   void SetSharedURLLoaderFactoryForTesting(
       scoped_refptr<network::SharedURLLoaderFactory> factory);
 
+  // Resets |current_screen_| when login screen has started.
+  void LoginScreenStarted();
+
   // Configure and show GAIA password changed screen.
   void ShowGaiaPasswordChangedScreen(const AccountId& account_id,
                                      bool has_error);
@@ -270,7 +273,6 @@ class WizardController {
   void OnResetScreenExit();
   void OnDeviceModificationCanceled();
   void OnSupervisionTransitionScreenExit();
-  void OnUpdateRequiredScreenExit();
   void OnOobeFlowFinished();
   void OnPackagedLicenseScreenExit(PackagedLicenseScreen::Result result);
   void OnActiveDirectoryPasswordChangeScreenExit();

chrome/browser/chromeos/policy/minimum_version_policy_handler_delegate_impl.cc

@@ -85,11 +85,11 @@ void MinimumVersionPolicyHandlerDelegateImpl::
       WizardController::default_controller();
   if (!wizard_controller)
     return;
-  chromeos::UpdateRequiredScreen* screen =
-      chromeos::UpdateRequiredScreen::Get(wizard_controller->screen_manager());
-  if (screen->is_hidden())
-    return;
-  screen->Exit();
+  chromeos::BaseScreen* screen = wizard_controller->current_screen();
+  if (screen &&
+      screen->screen_id() == chromeos::UpdateRequiredView::kScreenId) {
+    chromeos::LoginDisplayHost::default_host()->StartSignInScreen();
+  }
 }
 
 base::Version MinimumVersionPolicyHandlerDelegateImpl::GetCurrentVersion()

chrome/browser/chromeos/system/device_disabling_browsertest.cc

@@ -214,28 +214,6 @@ IN_PROC_BROWSER_TEST_F(DeviceDisablingTest, DisableWithEphemeralUsers) {
   test::CreateOobeScreenWaiter("device-disabled")->Wait();
 }
 
-class DeviceDisablingWithUsersTest : public DeviceDisablingTest {
- public:
-  DeviceDisablingWithUsersTest() { login_manager_.AppendRegularUsers(2); }
-
- private:
-  LoginManagerMixin login_manager_{&mixin_host_};
-};
-
-// Checks that OOBE dialog is not hidden when the device disabled screen is
-// shown and "StartSignInScreen" is called.
-IN_PROC_BROWSER_TEST_F(DeviceDisablingWithUsersTest, DialogNotHidden) {
-  EXPECT_TRUE(ash::LoginScreenTestApi::ClickAddUserButton());
-  EXPECT_TRUE(ash::LoginScreenTestApi::IsOobeDialogVisible());
-  OobeScreenWaiter(GaiaView::kScreenId).Wait();
-  MarkDisabledAndWaitForPolicyFetch();
-  OobeScreenWaiter(DeviceDisabledScreenView::kScreenId).Wait();
-  LoginDisplayHost::default_host()->StartSignInScreen();
-
-  // Dialog should not be hidden.
-  EXPECT_TRUE(ash::LoginScreenTestApi::IsOobeDialogVisible());
-}
-
 // Sets the device disabled policy before the browser is started.
 class PresetPolicyDeviceDisablingTest : public DeviceDisablingTest {
  public:

chrome/browser/resources/chromeos/login/screen_gaia_signin.js

@@ -711,6 +711,8 @@ Polymer({
    * Event handler that is invoked just before the frame is shown.
    */
   onBeforeShow() {
+    this.screenMode_ = AuthMode.DEFAULT;
+    this.loadingFrameContents_ = true;
     chrome.send('loginUIStateChanged', ['gaia-signin', true]);
 
     // Ensure that GAIA signin (or loading UI) is actually visible.

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

@@ -697,10 +697,8 @@ void GaiaScreenHandler::Initialize() {
   initialized_ = true;
   // This should be called only once on page load.
   AllowJavascript();
-  if (show_on_init_) {
-    show_on_init_ = false;
+  if (show_when_ready_)
     ShowGaiaScreenIfReady();
-  }
 }
 
 void GaiaScreenHandler::RegisterMessages() {
@@ -883,7 +881,7 @@ void GaiaScreenHandler::HandleCompleteAdAuthentication(
   if (LoginDisplayHost::default_host())
     LoginDisplayHost::default_host()->SetDisplayEmail(username);
 
-  populated_account_id_ = AccountId::FromUserEmail(username);
+  set_populated_account(AccountId::FromUserEmail(username));
   DCHECK(authpolicy_login_helper_);
   Key key(password);
   key.SetLabel(kCryptohomeGaiaKeyLabel);
@@ -927,15 +925,6 @@ void GaiaScreenHandler::HandleCompleteAuthentication(
   }
 
   ContinueAuthenticationWhenCookiesAvailable();
-
-  if (test_expects_complete_login_) {
-    VLOG(2) << "Complete test login for " << sanitized_email
-            << ", requested=" << test_user_;
-
-    test_expects_complete_login_ = false;
-    test_user_.clear();
-    test_pass_.clear();
-  }
 }
 
 void GaiaScreenHandler::ContinueAuthenticationWhenCookiesAvailable() {
@@ -1093,7 +1082,7 @@ void GaiaScreenHandler::HandleShowAddUser(const base::ListValue* args) {
   // |args| can be null if it's OOBE.
   if (args)
     args->GetString(0, &email);
-  populated_account_id_ = AccountId::FromUserEmail(email);
+  set_populated_account(AccountId::FromUserEmail(email));
   OnShowAddUser();
 }
 
@@ -1158,8 +1147,7 @@ void GaiaScreenHandler::HandleSecurityTokenPinEntered(
 void GaiaScreenHandler::OnShowAddUser() {
   signin_screen_handler_->is_account_picker_showing_first_time_ = false;
   lock_screen_utils::EnforceDevicePolicyInputMethods(std::string());
-  LoadGaiaAsync(EmptyAccountId());
-  LoginDisplayHost::default_host()->StartWizard(GaiaView::kScreenId);
+  ShowGaiaAsync(EmptyAccountId());
 }
 
 void GaiaScreenHandler::DoCompleteLogin(
@@ -1192,6 +1180,15 @@ void GaiaScreenHandler::DoCompleteLogin(
   }
 
   LoginDisplayHost::default_host()->CompleteLogin(user_context);
+
+  if (test_expects_complete_login_) {
+    VLOG(2) << "Complete test login for " << typed_email
+            << ", requested=" << test_user_;
+
+    test_expects_complete_login_ = false;
+    test_user_.clear();
+    test_pass_.clear();
+  }
 }
 
 void GaiaScreenHandler::StartClearingDnsCache() {
@@ -1273,8 +1270,8 @@ void GaiaScreenHandler::SubmitLoginFormForTest() {
                                      base::NullCallback());
   }
 
-  // Test properties are cleared in HandleCompleteAuthentication because the
-  // form submission might fail and login will not be attempted after reloading
+  // Test properties are cleared in HandleCompleteLogin because the form
+  // submission might fail and login will not be attempted after reloading
   // if they are cleared here.
 }
 
@@ -1286,18 +1283,10 @@ void GaiaScreenHandler::SetSAMLPrincipalsAPIUsed(bool is_third_party_idp,
   RecordAPILogin(is_third_party_idp, is_api_used);
 }
 
-void GaiaScreenHandler::Show() {
-  ShowScreen(GaiaView::kScreenId);
-  hidden_ = false;
-}
-
-void GaiaScreenHandler::Hide() {
-  hidden_ = true;
-}
-
-void GaiaScreenHandler::LoadGaiaAsync(const AccountId& account_id) {
+void GaiaScreenHandler::ShowGaiaAsync(const AccountId& account_id) {
   if (account_id.is_valid())
     populated_account_id_ = account_id;
+  show_when_ready_ = true;
   if (gaia_silent_load_ && !populated_account_id_.is_valid()) {
     dns_cleared_ = true;
     cookies_cleared_ = true;
@@ -1309,11 +1298,6 @@ void GaiaScreenHandler::LoadGaiaAsync(const AccountId& account_id) {
   }
 }
 
-void GaiaScreenHandler::LoadOfflineGaia(const AccountId& account_id) {
-  populated_account_id_ = account_id;
-  LoadAuthExtension(true /* force */, true /* offline */);
-}
-
 void GaiaScreenHandler::ShowSigninScreenForTest(const std::string& username,
                                                 const std::string& password,
                                                 const std::string& services) {
@@ -1397,12 +1381,13 @@ void GaiaScreenHandler::CreateSamlChallengeKeyHandler() {
   saml_challenge_key_handler_ = std::make_unique<SamlChallengeKeyHandler>();
 }
 
+void GaiaScreenHandler::CancelShowGaiaAsync() {
+  show_when_ready_ = false;
+}
+
 void GaiaScreenHandler::ShowGaiaScreenIfReady() {
-  if (!initialized_) {
-    show_on_init_ = true;
-    return;
-  }
-  if (!dns_cleared_ || !cookies_cleared_ || !LoginDisplayHost::default_host()) {
+  if (!dns_cleared_ || !cookies_cleared_ || !initialized_ ||
+      !show_when_ready_ || !LoginDisplayHost::default_host()) {
     return;
   }
 
@@ -1533,7 +1518,7 @@ void GaiaScreenHandler::SetOfflineLoginIsActive(bool is_active) {
 }
 
 void GaiaScreenHandler::UpdateState(NetworkError::ErrorReason reason) {
-  if (signin_screen_handler_ && !hidden_)
+  if (signin_screen_handler_)
     signin_screen_handler_->UpdateState(reason);
 }
 

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

@@ -58,17 +58,11 @@ class GaiaView {
 
   virtual void DisableRestrictiveProxyCheckForTest() = 0;
 
-  // Loads Gaia into the webview. Depending on internal state, the Gaia will
-  // either be loaded immediately or after an asynchronous clean-up process that
+  // Show the sign-in screen. Depending on internal state, the screen will
+  // either be shown immediately or after an asynchronous clean-up process that
   // cleans DNS cache and cookies. If available, |account_id| is used for
   // prefilling information.
-  virtual void LoadGaiaAsync(const AccountId& account_id) = 0;
-
-  virtual void LoadOfflineGaia(const AccountId& account_id) = 0;
-
-  // Shows Gaia screen.
-  virtual void Show() = 0;
-  virtual void Hide() = 0;
+  virtual void ShowGaiaAsync(const AccountId& account_id) = 0;
 
   // Show sign-in screen for the given credentials. |services| is a list of
   // services returned by userInfo call as JSON array. Should be an empty array
@@ -121,10 +115,7 @@ class GaiaScreenHandler : public BaseScreenHandler,
   // GaiaView:
   void MaybePreloadAuthExtension() override;
   void DisableRestrictiveProxyCheckForTest() override;
-  void LoadGaiaAsync(const AccountId& account_id) override;
-  void LoadOfflineGaia(const AccountId& account_id) override;
-  void Show() override;
-  void Hide() override;
+  void ShowGaiaAsync(const AccountId& account_id) override;
   void ShowSigninScreenForTest(const std::string& username,
                                const std::string& password,
                                const std::string& services) override;
@@ -260,6 +251,11 @@ class GaiaScreenHandler : public BaseScreenHandler,
                        bool using_saml,
                        const SamlPasswordAttributes& password_attributes);
 
+  // Fill GAIA account.
+  void set_populated_account(const AccountId& populated_account_id) {
+    populated_account_id_ = populated_account_id;
+  }
+
   // Kick off cookie / local storage cleanup.
   void StartClearingCookies(const base::Closure& on_clear_callback);
   void OnCookiesCleared(const base::Closure& on_clear_callback);
@@ -281,6 +277,10 @@ class GaiaScreenHandler : public BaseScreenHandler,
   // Chrome Credentials Passing API was used during SAML login.
   void SetSAMLPrincipalsAPIUsed(bool is_third_party_idp, bool is_api_used);
 
+  // Cancels the request to show the sign-in screen while the asynchronous
+  // clean-up process that precedes the screen showing is in progress.
+  void CancelShowGaiaAsync();
+
   // Shows signin screen after dns cache and cookie cleanup operations finish.
   void ShowGaiaScreenIfReady();
 
@@ -359,8 +359,6 @@ class GaiaScreenHandler : public BaseScreenHandler,
   // Whether the handler has been initialized.
   bool initialized_ = false;
 
-  bool show_on_init_ = false;
-
   // True if dns cache cleanup is done.
   bool dns_cleared_ = false;
 
@@ -447,8 +445,6 @@ class GaiaScreenHandler : public BaseScreenHandler,
   // canceled by the user.
   bool was_security_token_pin_canceled_ = false;
 
-  bool hidden_ = true;
-
   // Handler for |samlChallengeMachineKey| request.
   std::unique_ptr<SamlChallengeKeyHandler> saml_challenge_key_handler_;
   std::unique_ptr<SamlChallengeKeyHandler> saml_challenge_key_handler_for_test_;

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

@@ -45,7 +45,6 @@
 #include "chrome/browser/chromeos/login/quick_unlock/quick_unlock_factory.h"
 #include "chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage.h"
 #include "chrome/browser/chromeos/login/reauth_stats.h"
-#include "chrome/browser/chromeos/login/screens/gaia_screen.h"
 #include "chrome/browser/chromeos/login/screens/network_error.h"
 #include "chrome/browser/chromeos/login/startup_utils.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host.h"
@@ -521,9 +520,11 @@ void SigninScreenHandler::UpdateUIState(UIState ui_state) {
   switch (ui_state) {
     case UI_STATE_GAIA_SIGNIN:
       ui_state_ = UI_STATE_GAIA_SIGNIN;
+      ShowScreen(GaiaView::kScreenId);
       break;
     case UI_STATE_ACCOUNT_PICKER:
       ui_state_ = UI_STATE_ACCOUNT_PICKER;
+      gaia_screen_handler_->CancelShowGaiaAsync();
       ShowScreen(OobeScreen::SCREEN_ACCOUNT_PICKER);
       break;
     default:
@@ -867,9 +868,7 @@ void SigninScreenHandler::OnPreferencesChanged() {
     // We need to reload GAIA if UI_STATE_UNKNOWN or the allow new user setting
     // has changed so that reloaded GAIA shows/hides the option to create a new
     // account.
-    GaiaScreen* gaia_screen = GaiaScreen::Get(
-        WizardController::default_controller()->screen_manager());
-    gaia_screen->LoadOnline(EmptyAccountId());
+    UpdateUIState(UI_STATE_ACCOUNT_PICKER);
   }
 }
 
@@ -1057,13 +1056,8 @@ void SigninScreenHandler::HandleOfflineLogin(const base::ListValue* args) {
   std::string email;
   args->GetString(0, &email);
 
-  GaiaScreen* gaia_screen =
-      GaiaScreen::Get(WizardController::default_controller()->screen_manager());
-  gaia_screen->LoadOffline(AccountId::FromUserEmail(email));
-  HideOfflineMessage(NetworkStateInformer::OFFLINE,
-                     NetworkError::ERROR_REASON_NONE);
-  LoginDisplayHost::default_host()->StartWizard(GaiaView::kScreenId);
-
+  gaia_screen_handler_->set_populated_account(AccountId::FromUserEmail(email));
+  gaia_screen_handler_->LoadAuthExtension(true /* force */, true /* offline */);
   UpdateUIState(UI_STATE_GAIA_SIGNIN);
 }