Revert "cros: Make LoginDisplayHost own LoginDisplay"

This reverts commit 7f596585.

Reason for revert:

Findit (https://goo.gl/kROfz5) identified CL at revision 568084 as the
culprit for failures in the build cycles as shown on:
https://findit-for-me.appspot.com/waterfall/culprit?key=ag9zfmZpbmRpdC1mb3ItbWVyRAsSDVdmU3VzcGVjdGVkQ0wiMWNocm9taXVtLzdmNTk2NTg1YTM4MmI3ZDIzNDQ3NDAxOTY4OTU4OGUxOTE5ZDU2OWYM

Sample Failed Build: https://ci.chromium.org/buildbot/chromium.memory/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/27973

Sample Failed Step: unit_tests

Original change's description:
> cros: Make LoginDisplayHost own LoginDisplay
> 
> Instead of this ownership model
> 
>   LoginDisplayHost owns ExistingUserController owns LoginDisplay
>   LoginDisplayHost owns WebUIScreenLocker owns LoginDisplay
> 
> switch to
> 
>   LoginDisplayHost owns ExistingUserController, LoginDisplay
> 
> This makes it clear that the LoginDisplay instance has one owner, and
> that it shares the same lifetime as LoginDisplayHost.
> 
> Bug: 851012
> Change-Id: I80cb56d8fc244ce5331046ba31defba4cd77c45f
> Reviewed-on: https://chromium-review.googlesource.com/1093741
> Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
> Commit-Queue: Jacob Dufault <jdufault@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#568084}

Change-Id: I144f702fc39267db2ef830b276ca3c77c2c3c262
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 851012
Reviewed-on: https://chromium-review.googlesource.com/1105240
Cr-Commit-Position: refs/heads/master@{#568182}

chrome/browser/chromeos/login/existing_user_controller.cc

@@ -317,6 +317,7 @@ ExistingUserController* ExistingUserController::current_controller_ = nullptr;
 
 ExistingUserController::ExistingUserController(LoginDisplayHost* host)
     : host_(host),
+      login_display_(host_->CreateLoginDisplay(this)),
       cros_settings_(CrosSettings::Get()),
       network_state_helper_(new login::NetworkStateHelper),
       weak_factory_(this) {
@@ -411,9 +412,9 @@ void ExistingUserController::UpdateLoginDisplay(
   show_guest &= !filtered_users.empty();
   bool allow_new_user = true;
   cros_settings_->GetBoolean(kAccountsPrefAllowNewUser, &allow_new_user);
-  GetLoginDisplay()->set_parent_window(GetNativeWindow());
-  GetLoginDisplay()->Init(filtered_users, show_guest, show_users_on_signin,
-                          allow_new_user);
+  login_display_->set_parent_window(GetNativeWindow());
+  login_display_->Init(filtered_users, show_guest, show_users_on_signin,
+                       allow_new_user);
   host_->OnPreferencesChanged();
 }
 
@@ -510,6 +511,7 @@ ExistingUserController::~ExistingUserController() {
   } else {
     NOTREACHED() << "More than one controller are alive.";
   }
+  DCHECK(login_display_.get());
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -665,7 +667,7 @@ void ExistingUserController::ContinuePerformLoginWithoutMigration(
 void ExistingUserController::RestartLogin(const UserContext& user_context) {
   is_login_in_progress_ = false;
   login_performer_.reset();
-  GetLoginDisplay()->ShowSigninUI(user_context.GetAccountId().GetUserEmail());
+  login_display_->ShowSigninUI(user_context.GetAccountId().GetUserEmail());
 }
 
 void ExistingUserController::OnSigninScreenReady() {
@@ -800,8 +802,8 @@ void ExistingUserController::ShowEncryptionMigrationScreen(
 }
 
 void ExistingUserController::ShowTPMError() {
-  GetLoginDisplay()->SetUIEnabled(false);
-  GetLoginDisplay()->ShowErrorScreen(LoginDisplay::TPM_ERROR);
+  login_display_->SetUIEnabled(false);
+  login_display_->ShowErrorScreen(LoginDisplay::TPM_ERROR);
 }
 
 void ExistingUserController::ShowPasswordChangedDialog() {
@@ -819,8 +821,8 @@ void ExistingUserController::ShowPasswordChangedDialog() {
   // us to recover from a lost owner password/homedir.
   // TODO(gspencer): We shouldn't have to erase stateful data when
   // doing this.  See http://crosbug.com/9115 http://crosbug.com/7792
-  GetLoginDisplay()->ShowPasswordChangedDialog(show_invalid_old_password_error,
-                                               display_email_);
+  login_display_->ShowPasswordChangedDialog(show_invalid_old_password_error,
+                                            display_email_);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -854,7 +856,7 @@ void ExistingUserController::OnAuthFailure(const AuthFailure& failure) {
     ShowTPMError();
   } else if (last_login_attempt_account_id_ == user_manager::GuestAccountId()) {
     // Show no errors, just re-enable input.
-    GetLoginDisplay()->ClearAndEnablePassword();
+    login_display_->ClearAndEnablePassword();
     StartAutoLoginTimer();
   } else if (is_known_user &&
              failure.reason() == AuthFailure::MISSING_CRYPTOHOME) {
@@ -879,7 +881,7 @@ void ExistingUserController::OnAuthFailure(const AuthFailure& failure) {
     if (auth_flow_offline_)
       UMA_HISTOGRAM_BOOLEAN("Login.OfflineFailure.IsKnownUser", is_known_user);
 
-    GetLoginDisplay()->ClearAndEnablePassword();
+    login_display_->ClearAndEnablePassword();
     StartAutoLoginTimer();
   }
 
@@ -896,7 +898,7 @@ void ExistingUserController::OnAuthFailure(const AuthFailure& failure) {
 
 void ExistingUserController::OnAuthSuccess(const UserContext& user_context) {
   is_login_in_progress_ = false;
-  GetLoginDisplay()->set_signin_completed(true);
+  login_display_->set_signin_completed(true);
 
   // Login performer will be gone so cache this value to use
   // once profile is loaded.
@@ -968,7 +970,7 @@ void ExistingUserController::OnAuthSuccess(const UserContext& user_context) {
 void ExistingUserController::OnProfilePrepared(Profile* profile,
                                                bool browser_launched) {
   // Reenable clicking on other windows and status area.
-  GetLoginDisplay()->SetUIEnabled(true);
+  login_display_->SetUIEnabled(true);
 
   if (browser_launched)
     host_ = nullptr;
@@ -1186,13 +1188,13 @@ void ExistingUserController::ForceOnlineLoginForAccountId(
   // Start online sign-in UI for the user.
   is_login_in_progress_ = false;
   login_performer_.reset();
-  GetLoginDisplay()->ShowSigninUI(account_id.GetUserEmail());
+  login_display_->ShowSigninUI(account_id.GetUserEmail());
 }
 
 void ExistingUserController::WhiteListCheckFailed(const std::string& email) {
   PerformLoginFinishedActions(true /* start auto login timer */);
 
-  GetLoginDisplay()->ShowWhitelistCheckFailedError();
+  login_display_->ShowWhitelistCheckFailedError();
 
   if (auth_status_consumer_) {
     auth_status_consumer_->OnAuthFailure(
@@ -1221,7 +1223,7 @@ void ExistingUserController::SetAuthFlowOffline(bool offline) {
 void ExistingUserController::DeviceSettingsChanged() {
   // If login was already completed, we should avoid any signin screen
   // transitions, see http://crbug.com/461604 for example.
-  if (host_ != nullptr && !GetLoginDisplay()->is_signin_completed()) {
+  if (host_ != nullptr && !login_display_->is_signin_completed()) {
     // Signed settings or user list changed. Notify views and update them.
     UpdateLoginDisplay(user_manager::UserManager::Get()->GetUsers());
     ConfigureAutoLogin();
@@ -1242,10 +1244,6 @@ bool ExistingUserController::password_changed() const {
   return password_changed_;
 }
 
-LoginDisplay* ExistingUserController::GetLoginDisplay() {
-  return host_->GetLoginDisplay();
-}
-
 void ExistingUserController::LoginAsGuest() {
   PerformPreLoginActions(UserContext(user_manager::USER_TYPE_GUEST,
                                      user_manager::GuestAccountId()));
@@ -1508,7 +1506,7 @@ void ExistingUserController::ShowError(int error_id,
     }
   }
 
-  GetLoginDisplay()->ShowError(error_id, num_login_attempts_, help_topic_id);
+  login_display_->ShowError(error_id, num_login_attempts_, help_topic_id);
 }
 
 void ExistingUserController::SendAccessibilityAlert(
@@ -1551,7 +1549,7 @@ void ExistingUserController::LoginAsPublicSessionInternal(
 void ExistingUserController::PerformPreLoginActions(
     const UserContext& user_context) {
   // Disable clicking on other windows and status tray.
-  GetLoginDisplay()->SetUIEnabled(false);
+  login_display_->SetUIEnabled(false);
 
   if (last_login_attempt_account_id_ != user_context.GetAccountId()) {
     last_login_attempt_account_id_ = user_context.GetAccountId();
@@ -1568,7 +1566,7 @@ void ExistingUserController::PerformLoginFinishedActions(
   is_login_in_progress_ = false;
 
   // Reenable clicking on other windows and status area.
-  GetLoginDisplay()->SetUIEnabled(true);
+  login_display_->SetUIEnabled(true);
 
   if (start_auto_login_timer)
     StartAutoLoginTimer();
@@ -1588,7 +1586,7 @@ void ExistingUserController::ContinueLoginWhenCryptohomeAvailable(
 void ExistingUserController::ContinueLoginIfDeviceNotDisabled(
     const base::Closure& continuation) {
   // Disable clicking on other windows and status tray.
-  GetLoginDisplay()->SetUIEnabled(false);
+  login_display_->SetUIEnabled(false);
 
   // Stop the auto-login timer.
   StopAutoLoginTimer();
@@ -1605,13 +1603,13 @@ void ExistingUserController::ContinueLoginIfDeviceNotDisabled(
   if (status == CrosSettingsProvider::PERMANENTLY_UNTRUSTED) {
     // If the |cros_settings_| are permanently untrusted, show an error message
     // and refuse to log in.
-    GetLoginDisplay()->ShowError(IDS_LOGIN_ERROR_OWNER_KEY_LOST, 1,
-                                 HelpAppLauncher::HELP_CANT_ACCESS_ACCOUNT);
+    login_display_->ShowError(IDS_LOGIN_ERROR_OWNER_KEY_LOST, 1,
+                              HelpAppLauncher::HELP_CANT_ACCESS_ACCOUNT);
 
     // Re-enable clicking on other windows and the status area. Do not start the
     // auto-login timer though. Without trusted |cros_settings_|, no auto-login
     // can succeed.
-    GetLoginDisplay()->SetUIEnabled(true);
+    login_display_->SetUIEnabled(true);
     return;
   }
 
@@ -1621,7 +1619,7 @@ void ExistingUserController::ContinueLoginIfDeviceNotDisabled(
 
     // Re-enable clicking on other windows and the status area. Do not start the
     // auto-login timer though. On a disabled device, no auto-login can succeed.
-    GetLoginDisplay()->SetUIEnabled(true);
+    login_display_->SetUIEnabled(true);
     return;
   }
 
@@ -1708,7 +1706,7 @@ void ExistingUserController::DoLogin(const UserContext& user_context,
     // If credentials are missing, refuse to log in.
 
     // Reenable clicking on other windows and status area.
-    GetLoginDisplay()->SetUIEnabled(true);
+    login_display_->SetUIEnabled(true);
     // Restart the auto-login timer.
     StartAutoLoginTimer();
   }
@@ -1744,7 +1742,7 @@ void ExistingUserController::OnTokenHandleChecked(
   // permission to collect a feedback.
   RecordPasswordChangeFlow(LOGIN_PASSWORD_CHANGE_FLOW_CRYPTOHOME_FAILURE);
   VLOG(1) << "Show unrecoverable cryptohome error dialog.";
-  GetLoginDisplay()->ShowUnrecoverableCrypthomeErrorDialog();
+  login_display_->ShowUnrecoverableCrypthomeErrorDialog();
 }
 
 void ExistingUserController::ClearRecordedNames() {

chrome/browser/chromeos/login/existing_user_controller.h

@@ -49,7 +49,7 @@ class CloudPolicySettings;
 namespace chromeos {
 
 class CrosSettings;
-class LoginDisplay;
+class LoginDisplayHost;
 class OAuth2TokenInitializer;
 
 namespace login {
@@ -139,6 +139,13 @@ class ExistingUserController
     auth_status_consumer_ = consumer;
   }
 
+  // Returns the LoginDisplay created and owned by this controller.
+  // Used for testing.
+  LoginDisplay* login_display() { return login_display_.get(); }
+
+  // Returns the LoginDisplayHost for this controller.
+  LoginDisplayHost* login_display_host() { return host_; }
+
   // Returns value of LoginPerformer::auth_mode() (cached if performer is
   // destroyed).
   LoginPerformer::AuthorizationMode auth_mode() const;
@@ -155,9 +162,6 @@ class ExistingUserController
 
   FRIEND_TEST_ALL_PREFIXES(ExistingUserControllerTest, ExistingUserLogin);
 
-  // Login UI implementation instance.
-  LoginDisplay* GetLoginDisplay();
-
   void LoginAsGuest();
   void LoginAsPublicSession(const UserContext& user_context);
   void LoginAsKioskApp(const std::string& app_id, bool diagnostic_mode);
@@ -212,6 +216,9 @@ class ExistingUserController
   // Shows "enable developer features" screen.
   void ShowEnableDebuggingScreen();
 
+  // Shows demo mode setup screen.
+  void ShowDemoModeSetupScreen();
+
   // Shows kiosk feature enable screen.
   void ShowKioskEnableScreen();
 
@@ -348,6 +355,9 @@ class ExistingUserController
   // OOBE/login display host.
   LoginDisplayHost* host_;
 
+  // Login UI implementation instance.
+  std::unique_ptr<LoginDisplay> login_display_;
+
   // Number of login attempts. Used to show help link when > 1 unsuccessful
   // logins for the same user.
   size_t num_login_attempts_ = 0;

chrome/browser/chromeos/login/existing_user_controller_auto_login_unittest.cc

@@ -51,8 +51,9 @@ class ExistingUserControllerAutoLoginTest : public ::testing::Test {
     mock_login_display_ = new MockLoginDisplay();
     arc_kiosk_app_manager_.reset(new ArcKioskAppManager());
 
-    ON_CALL(*mock_login_display_host_, GetLoginDisplay())
-        .WillByDefault(Return(mock_login_display_));
+    EXPECT_CALL(*mock_login_display_host_.get(), CreateLoginDisplay(_))
+        .Times(1)
+        .WillOnce(Return(mock_login_display_));
 
     EXPECT_CALL(*mock_user_manager_, Shutdown()).Times(AnyNumber());
     EXPECT_CALL(*mock_user_manager_, FindUser(_)).WillRepeatedly(ReturnNull());

chrome/browser/chromeos/login/existing_user_controller_browsertest.cc

@@ -204,21 +204,22 @@ class ExistingUserControllerTest : public policy::DevicePolicyCrosBrowserTest {
 
     DevicePolicyCrosBrowserTest::SetUpInProcessBrowserTestFixture();
 
-    mock_login_display_host_ = std::make_unique<MockLoginDisplayHost>();
-    mock_login_display_ = std::make_unique<MockLoginDisplay>();
+    mock_login_display_host_.reset(new MockLoginDisplayHost());
+    mock_login_display_ = new MockLoginDisplay();
     SetUpLoginDisplay();
   }
 
   virtual void SetUpSessionManager() {}
 
   virtual void SetUpLoginDisplay() {
-    EXPECT_CALL(*mock_login_display_host_, GetLoginDisplay())
-        .Times(AnyNumber())
-        .WillRepeatedly(Return(mock_login_display_.get()));
-    EXPECT_CALL(*mock_login_display_host_, GetNativeWindow())
+    EXPECT_CALL(*mock_login_display_host_.get(), CreateLoginDisplay(_))
+        .Times(1)
+        .WillOnce(Return(mock_login_display_));
+    EXPECT_CALL(*mock_login_display_host_.get(), GetNativeWindow())
         .Times(1)
         .WillOnce(ReturnNull());
-    EXPECT_CALL(*mock_login_display_host_, OnPreferencesChanged()).Times(1);
+    EXPECT_CALL(*mock_login_display_host_.get(), OnPreferencesChanged())
+        .Times(1);
     EXPECT_CALL(*mock_login_display_, Init(_, false, true, true)).Times(1);
   }
 
@@ -288,7 +289,9 @@ class ExistingUserControllerTest : public policy::DevicePolicyCrosBrowserTest {
 
   std::unique_ptr<ExistingUserController> existing_user_controller_;
 
-  std::unique_ptr<MockLoginDisplay> mock_login_display_;
+  // |mock_login_display_| is owned by the ExistingUserController, which calls
+  // CreateLoginDisplay() on the |mock_login_display_host_| to get it.
+  MockLoginDisplay* mock_login_display_ = nullptr;
   std::unique_ptr<MockLoginDisplayHost> mock_login_display_host_;
 
   // Mock URLFetcher.
@@ -478,9 +481,9 @@ class ExistingUserControllerPublicSessionTest
   }
 
   void SetUpLoginDisplay() override {
-    EXPECT_CALL(*mock_login_display_host_, GetLoginDisplay())
-        .Times(AnyNumber())
-        .WillRepeatedly(Return(mock_login_display_.get()));
+    EXPECT_CALL(*mock_login_display_host_.get(), CreateLoginDisplay(_))
+        .Times(1)
+        .WillOnce(Return(mock_login_display_));
     EXPECT_CALL(*mock_login_display_host_.get(), GetNativeWindow())
         .Times(AnyNumber())
         .WillRepeatedly(ReturnNull());
@@ -952,13 +955,14 @@ class ExistingUserControllerActiveDirectoryUserWhitelistTest
   }
 
   void SetUpLoginDisplay() override {
-    EXPECT_CALL(*mock_login_display_host_, GetLoginDisplay())
-        .Times(AnyNumber())
-        .WillRepeatedly(Return(mock_login_display_.get()));
-    EXPECT_CALL(*mock_login_display_host_, GetNativeWindow())
+    EXPECT_CALL(*mock_login_display_host_.get(), CreateLoginDisplay(_))
+        .Times(1)
+        .WillOnce(Return(mock_login_display_));
+    EXPECT_CALL(*mock_login_display_host_.get(), GetNativeWindow())
         .Times(1)
         .WillOnce(ReturnNull());
-    EXPECT_CALL(*mock_login_display_host_, OnPreferencesChanged()).Times(1);
+    EXPECT_CALL(*mock_login_display_host_.get(), OnPreferencesChanged())
+        .Times(1);
     EXPECT_CALL(*mock_login_display_, Init(_, false, true, false)).Times(1);
   }
 };

chrome/browser/chromeos/login/lock/webui_screen_locker.cc

@@ -156,10 +156,10 @@ void WebUIScreenLocker::LockScreen() {
   LoadURL(GURL(kLoginURL));
   OnLockWindowReady();
 
-  signin_screen_controller_.reset(new SignInScreenController(GetOobeUI()));
+  signin_screen_controller_.reset(
+      new SignInScreenController(GetOobeUI(), this));
 
-  login_display_.reset(new LoginDisplayWebUI());
-  login_display_->set_delegate(this);
+  login_display_.reset(new LoginDisplayWebUI(this));
   login_display_->set_parent_window(GetNativeWindow());
   login_display_->Init(screen_locker_->users(), false, true, false);
 

chrome/browser/chromeos/login/oobe_browsertest.cc

@@ -8,10 +8,12 @@
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/chromeos/login/existing_user_controller.h"
 #include "chrome/browser/chromeos/login/screens/gaia_view.h"
 #include "chrome/browser/chromeos/login/test/oobe_base_test.h"
 #include "chrome/browser/chromeos/login/test/oobe_screen_waiter.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host_webui.h"
+#include "chrome/browser/chromeos/login/ui/login_display_webui.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h"
@@ -53,8 +55,9 @@ class OobeTest : public OobeBaseTest {
     OobeBaseTest::TearDownOnMainThread();
   }
 
-  LoginDisplay* GetLoginDisplay() {
-    return LoginDisplayHost::default_host()->GetLoginDisplay();
+  LoginDisplayWebUI* GetLoginDisplay() {
+    return static_cast<LoginDisplayWebUI*>(
+        ExistingUserController::current_controller()->login_display());
   }
 
   views::Widget* GetLoginWindowWidget() {

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

@@ -360,6 +360,11 @@ void UserSelectionScreen::InitEasyUnlock() {
   proximity_auth::ScreenlockBridge::Get()->SetLockHandler(this);
 }
 
+void UserSelectionScreen::SetLoginDisplayDelegate(
+    LoginDisplay::Delegate* login_display_delegate) {
+  login_display_delegate_ = login_display_delegate;
+}
+
 // static
 void UserSelectionScreen::FillUserDictionary(
     user_manager::User* user,
@@ -754,11 +759,9 @@ void UserSelectionScreen::AttemptEasySignin(const AccountId& account_id,
   user_context.SetKey(Key(secret));
   user_context.GetKey()->SetLabel(key_label);
 
-  // LoginDisplayHost does not exist in views-based lock screen.
-  if (LoginDisplayHost::default_host()) {
-    LoginDisplayHost::default_host()->GetLoginDisplay()->delegate()->Login(
-        user_context, SigninSpecifics());
-  }
+  // login display delegate not exist in views-based lock screen.
+  if (login_display_delegate_)
+    login_display_delegate_->Login(user_context, SigninSpecifics());
 }
 
 void UserSelectionScreen::Show() {}

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

@@ -39,6 +39,7 @@ class UserSelectionScreen
   explicit UserSelectionScreen(const std::string& display_type);
   ~UserSelectionScreen() override;
 
+  void SetLoginDisplayDelegate(LoginDisplay::Delegate* login_display_delegate);
   void SetHandler(LoginDisplayWebUIHandler* handler);
   void SetView(UserBoardView* view);
 
@@ -151,6 +152,7 @@ class UserSelectionScreen
                            TokenHandleUtil::TokenHandleStatus status);
 
   LoginDisplayWebUIHandler* handler_ = nullptr;
+  LoginDisplay::Delegate* login_display_delegate_ = nullptr;
 
   // Purpose of the screen (see constants in OobeUI).
   const std::string display_type_;

chrome/browser/chromeos/login/session/chrome_session_manager_browsertest.cc

@@ -15,6 +15,7 @@
 #include "chrome/browser/chromeos/login/startup_utils.h"
 #include "chrome/browser/chromeos/login/test/oobe_screen_waiter.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host.h"
+#include "chrome/browser/chromeos/login/ui/login_display_webui.h"
 #include "chrome/browser/chromeos/login/ui/user_adding_screen.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 #include "chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h"

chrome/browser/chromeos/login/signin_screen_controller.cc

@@ -16,7 +16,9 @@ namespace chromeos {
 
 SignInScreenController* SignInScreenController::instance_ = nullptr;
 
-SignInScreenController::SignInScreenController(OobeUI* oobe_ui)
+SignInScreenController::SignInScreenController(
+    OobeUI* oobe_ui,
+    LoginDisplay::Delegate* login_display_delegate)
     : oobe_ui_(oobe_ui), gaia_screen_(new GaiaScreen()) {
   DCHECK(!instance_);
   instance_ = this;
@@ -24,6 +26,7 @@ SignInScreenController::SignInScreenController(OobeUI* oobe_ui)
   gaia_screen_->set_view(oobe_ui_->GetGaiaScreenView());
   std::string display_type = oobe_ui->display_type();
   user_selection_screen_.reset(new ChromeUserSelectionScreen(display_type));
+  user_selection_screen_->SetLoginDisplayDelegate(login_display_delegate);
 
   user_board_view_ = oobe_ui_->GetUserBoardView()->GetWeakPtr();
   user_selection_screen_->SetView(user_board_view_.get());

chrome/browser/chromeos/login/signin_screen_controller.h

@@ -33,7 +33,8 @@ class SignInScreenController : public user_manager::RemoveUserDelegate,
                                public user_manager::UserManager::Observer,
                                public content::NotificationObserver {
  public:
-  explicit SignInScreenController(OobeUI* oobe_ui);
+  SignInScreenController(OobeUI* oobe_ui,
+                         LoginDisplay::Delegate* login_display_delegate);
   ~SignInScreenController() override;
 
   // Returns the default wizard controller if it has been created.

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

@@ -29,7 +29,8 @@ FakeLoginDisplayHost::FakeLoginDisplayHost()
 
 FakeLoginDisplayHost::~FakeLoginDisplayHost() = default;
 
-LoginDisplay* FakeLoginDisplayHost::GetLoginDisplay() {
+LoginDisplay* FakeLoginDisplayHost::CreateLoginDisplay(
+    LoginDisplay::Delegate* delegate) {
   return nullptr;
 }
 

chrome/browser/chromeos/login/ui/fake_login_display_host.h

@@ -23,7 +23,7 @@ class FakeLoginDisplayHost : public LoginDisplayHost {
   ~FakeLoginDisplayHost() override;
 
   // chromeos::LoginDisplayHost:
-  LoginDisplay* GetLoginDisplay() override;
+  LoginDisplay* CreateLoginDisplay(LoginDisplay::Delegate* delegate) override;
   gfx::NativeWindow GetNativeWindow() const override;
   OobeUI* GetOobeUI() const override;
   WebUILoginView* GetWebUILoginView() const override;

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

@@ -8,7 +8,7 @@ namespace chromeos {
 
 LoginDisplay::Delegate::~Delegate() = default;
 
-LoginDisplay::LoginDisplay() = default;
+LoginDisplay::LoginDisplay(Delegate* delegate) : delegate_(delegate) {}
 
 LoginDisplay::~LoginDisplay() = default;
 

chrome/browser/chromeos/login/ui/login_display.h

@@ -79,7 +79,7 @@ class LoginDisplay {
     virtual ~Delegate();
   };
 
-  LoginDisplay();
+  explicit LoginDisplay(Delegate* delegate);
   virtual ~LoginDisplay();
 
   // Clears and enables fields on user pod or GAIA frame.

chrome/browser/chromeos/login/ui/login_display_host.h

@@ -52,8 +52,10 @@ class LoginDisplayHost {
   // Returns the default LoginDisplayHost instance if it has been created.
   static LoginDisplayHost* default_host() { return default_host_; }
 
-  // Returns an unowned pointer to the LoginDisplay* instance.
-  virtual LoginDisplay* GetLoginDisplay() = 0;
+  // Creates UI implementation specific login display instance (views/WebUI).
+  // The caller takes ownership of the returned value.
+  virtual LoginDisplay* CreateLoginDisplay(
+      LoginDisplay::Delegate* delegate) = 0;
 
   // Returns corresponding native window.
   virtual gfx::NativeWindow GetNativeWindow() const = 0;

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

@@ -31,8 +31,7 @@ constexpr char kAccelSendFeedback[] = "send_feedback";
 }  // namespace
 
 LoginDisplayHostMojo::LoginDisplayHostMojo()
-    : login_display_(std::make_unique<LoginDisplayMojo>(this)),
-      user_board_view_mojo_(std::make_unique<UserBoardViewMojo>()),
+    : user_board_view_mojo_(std::make_unique<UserBoardViewMojo>()),
       user_selection_screen_(
           std::make_unique<ChromeUserSelectionScreen>(kLoginDisplay)),
       weak_factory_(this) {
@@ -94,8 +93,13 @@ void LoginDisplayHostMojo::ShowSigninUI(const std::string& email) {
   dialog_->Show(true /*closable_by_esc*/);
 }
 
-LoginDisplay* LoginDisplayHostMojo::GetLoginDisplay() {
-  return login_display_.get();
+LoginDisplay* LoginDisplayHostMojo::CreateLoginDisplay(
+    LoginDisplay::Delegate* delegate) {
+  user_selection_screen_->SetLoginDisplayDelegate(delegate);
+  LoginDisplayMojo* login_display = new LoginDisplayMojo(delegate, this);
+  if (GetOobeUI())
+    GetOobeUI()->signin_screen_handler()->SetDelegate(login_display);
+  return login_display;
 }
 
 gfx::NativeWindow LoginDisplayHostMojo::GetNativeWindow() const {
@@ -169,7 +173,6 @@ void LoginDisplayHostMojo::OnStartSignInScreen(
   // There can only be one |ExistingUserController| instance at a time.
   existing_user_controller_.reset();
   existing_user_controller_ = std::make_unique<ExistingUserController>(this);
-  login_display_->set_delegate(existing_user_controller_.get());
 
   // We need auth attempt results to notify views-based lock screen.
   existing_user_controller_->set_login_status_consumer(this);

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

@@ -18,7 +18,6 @@
 namespace chromeos {
 
 class ExistingUserController;
-class LoginDisplayMojo;
 class OobeUIDialogDelegate;
 class UserBoardViewMojo;
 class UserSelectionScreen;
@@ -65,7 +64,7 @@ class LoginDisplayHostMojo : public LoginDisplayHostCommon,
   }
 
   // LoginDisplayHost:
-  LoginDisplay* GetLoginDisplay() override;
+  LoginDisplay* CreateLoginDisplay(LoginDisplay::Delegate* delegate) override;
   gfx::NativeWindow GetNativeWindow() const override;
   OobeUI* GetOobeUI() const override;
   WebUILoginView* GetWebUILoginView() const override;
@@ -118,8 +117,6 @@ class LoginDisplayHostMojo : public LoginDisplayHostCommon,
   // Callback that should be executed the authentication result is available.
   AuthenticateUserCallback on_authenticated_;
 
-  std::unique_ptr<LoginDisplayMojo> login_display_;
-
   std::unique_ptr<UserBoardViewMojo> user_board_view_mojo_;
   std::unique_ptr<UserSelectionScreen> user_selection_screen_;
 

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

@@ -490,8 +490,6 @@ LoginDisplayHostWebUI::LoginDisplayHostWebUI()
   ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
   manager->Initialize(SOUND_STARTUP,
                       bundle.GetRawDataResource(IDR_SOUND_STARTUP_WAV));
-
-  login_display_ = std::make_unique<LoginDisplayWebUI>();
 }
 
 LoginDisplayHostWebUI::~LoginDisplayHostWebUI() {
@@ -530,8 +528,10 @@ LoginDisplayHostWebUI::~LoginDisplayHostWebUI() {
 ////////////////////////////////////////////////////////////////////////////////
 // LoginDisplayHostWebUI, LoginDisplayHost:
 
-LoginDisplay* LoginDisplayHostWebUI::GetLoginDisplay() {
-  return login_display_.get();
+LoginDisplay* LoginDisplayHostWebUI::CreateLoginDisplay(
+    LoginDisplay::Delegate* delegate) {
+  login_display_ = new LoginDisplayWebUI(delegate);
+  return login_display_;
 }
 
 gfx::NativeWindow LoginDisplayHostWebUI::GetNativeWindow() const {
@@ -651,7 +651,8 @@ void LoginDisplayHostWebUI::OnStartUserAdding() {
   existing_user_controller_.reset(new ExistingUserController(this));
 
   if (!signin_screen_controller_.get()) {
-    signin_screen_controller_.reset(new SignInScreenController(GetOobeUI()));
+    signin_screen_controller_.reset(
+        new SignInScreenController(GetOobeUI(), login_display_->delegate()));
   }
 
   SetOobeProgressBarVisible(oobe_progress_bar_visible_ = false);
@@ -659,8 +660,8 @@ void LoginDisplayHostWebUI::OnStartUserAdding() {
   existing_user_controller_->Init(
       user_manager::UserManager::Get()->GetUsersAllowedForMultiProfile());
   CHECK(login_display_);
-  GetOobeUI()->ShowSigninScreen(LoginScreenContext(), login_display_.get(),
-                                login_display_.get());
+  GetOobeUI()->ShowSigninScreen(LoginScreenContext(), login_display_,
+                                login_display_);
 }
 
 void LoginDisplayHostWebUI::CancelUserAdding() {
@@ -700,10 +701,10 @@ void LoginDisplayHostWebUI::OnStartSignInScreen(
   DVLOG(1) << "Starting sign in screen";
   existing_user_controller_.reset();  // Only one controller in a time.
   existing_user_controller_.reset(new ExistingUserController(this));
-  login_display_->set_delegate(existing_user_controller_.get());
 
   if (!signin_screen_controller_.get()) {
-    signin_screen_controller_.reset(new SignInScreenController(GetOobeUI()));
+    signin_screen_controller_.reset(
+        new SignInScreenController(GetOobeUI(), login_display_->delegate()));
   }
 
   // TODO(crbug.com/784495): This is always false, since
@@ -713,8 +714,7 @@ void LoginDisplayHostWebUI::OnStartSignInScreen(
   existing_user_controller_->Init(user_manager::UserManager::Get()->GetUsers());
 
   CHECK(login_display_);
-  GetOobeUI()->ShowSigninScreen(context, login_display_.get(),
-                                login_display_.get());
+  GetOobeUI()->ShowSigninScreen(context, login_display_, login_display_);
   TRACE_EVENT_ASYNC_STEP_INTO0("ui", "ShowLoginWebUI", kShowLoginWebUIid,
                                "WaitForScreenStateInitialize");
 
@@ -1135,7 +1135,7 @@ void LoginDisplayHostWebUI::OnLoginPromptVisible() {
 
 // static
 void LoginDisplayHostWebUI::DisableRestrictiveProxyCheckForTest() {
-  default_host()
+  static_cast<LoginDisplayHostWebUI*>(default_host())
       ->GetOobeUI()
       ->GetGaiaScreenView()
       ->DisableRestrictiveProxyCheckForTest();

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

@@ -54,7 +54,7 @@ class LoginDisplayHostWebUI : public LoginDisplayHostCommon,
   ~LoginDisplayHostWebUI() override;
 
   // LoginDisplayHost:
-  LoginDisplay* GetLoginDisplay() override;
+  LoginDisplay* CreateLoginDisplay(LoginDisplay::Delegate* delegate) override;
   gfx::NativeWindow GetNativeWindow() const override;
   OobeUI* GetOobeUI() const override;
   WebUILoginView* GetWebUILoginView() const override;
@@ -197,7 +197,7 @@ class LoginDisplayHostWebUI : public LoginDisplayHostCommon,
   WebUILoginView* login_view_ = nullptr;
 
   // Login display we are using.
-  std::unique_ptr<LoginDisplayWebUI> login_display_;
+  LoginDisplayWebUI* login_display_ = nullptr;
 
   // True if the login display is the current screen.
   bool is_showing_login_ = false;

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

@@ -24,14 +24,17 @@
 
 namespace chromeos {
 
-LoginDisplayMojo::LoginDisplayMojo(LoginDisplayHostMojo* host) : host_(host) {
+LoginDisplayMojo::LoginDisplayMojo(Delegate* delegate,
+                                   LoginDisplayHostMojo* host)
+    : LoginDisplay(delegate), host_(host) {
   user_manager::UserManager::Get()->AddObserver(this);
-  if (host_->GetOobeUI())
-    host_->GetOobeUI()->signin_screen_handler()->SetDelegate(this);
 }
 
 LoginDisplayMojo::~LoginDisplayMojo() {
   user_manager::UserManager::Get()->RemoveObserver(this);
+
+  // Make sure SigninScreenHandler does not hold a reference to LoginDisplayMojo
+  // after it is deleted.
   if (host_->GetOobeUI())
     host_->GetOobeUI()->signin_screen_handler()->SetDelegate(nullptr);
 }

chrome/browser/chromeos/login/ui/login_display_mojo.h

@@ -22,7 +22,7 @@ class LoginDisplayMojo : public LoginDisplay,
                          public SigninScreenHandlerDelegate,
                          public user_manager::UserManager::Observer {
  public:
-  explicit LoginDisplayMojo(LoginDisplayHostMojo* host);
+  LoginDisplayMojo(Delegate* delegate, LoginDisplayHostMojo* host);
   ~LoginDisplayMojo() override;
 
   // LoginDisplay:

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

@@ -41,7 +41,8 @@ LoginDisplayWebUI::~LoginDisplayWebUI() {
 
 // LoginDisplay implementation: ------------------------------------------------
 
-LoginDisplayWebUI::LoginDisplayWebUI() = default;
+LoginDisplayWebUI::LoginDisplayWebUI(LoginDisplay::Delegate* delegate)
+    : LoginDisplay(delegate) {}
 
 void LoginDisplayWebUI::ClearAndEnablePassword() {
   if (webui_handler_)

chrome/browser/chromeos/login/ui/login_display_webui.h

@@ -27,7 +27,7 @@ class LoginDisplayWebUI : public LoginDisplay,
                           public SigninScreenHandlerDelegate,
                           public ui::UserActivityObserver {
  public:
-  LoginDisplayWebUI();
+  explicit LoginDisplayWebUI(LoginDisplay::Delegate* delegate);
   ~LoginDisplayWebUI() override;
 
   // LoginDisplay implementation:

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

@@ -10,7 +10,7 @@
 
 namespace chromeos {
 
-MockLoginDisplay::MockLoginDisplay() = default;
+MockLoginDisplay::MockLoginDisplay() : LoginDisplay(nullptr) {}
 
 MockLoginDisplay::~MockLoginDisplay() = default;
 

chrome/browser/chromeos/login/ui/mock_login_display_host.h

@@ -19,7 +19,7 @@ class MockLoginDisplayHost : public LoginDisplayHost {
   MockLoginDisplayHost();
   virtual ~MockLoginDisplayHost();
 
-  MOCK_METHOD0(GetLoginDisplay, LoginDisplay*());
+  MOCK_METHOD1(CreateLoginDisplay, LoginDisplay*(LoginDisplay::Delegate*));
   MOCK_CONST_METHOD0(GetNativeWindow, gfx::NativeWindow(void));
   MOCK_CONST_METHOD0(GetOobeUI, OobeUI*(void));
   MOCK_CONST_METHOD0(GetWebUILoginView, WebUILoginView*(void));