Reland "Reland "[CrOS] Introduce Kiosk app default message for Kiosk

SKU""

This is a reland of commit 91bed44fa3

Original change's description:
> Reland "[CrOS] Introduce Kiosk app default message for Kiosk SKU"
>
> This is a reland of commit f831febf00
>
> Revert CL is crrev.com/c/3586949.
>
> Original change's description:
> > [CrOS] Introduce Kiosk app default message for Kiosk SKU
> >
> > For device with kiosk SKU, a kiosk app default message would be shown
> > if kiosk apps are not set up. (go/kiosk-sku-prd)
> >
> > Implementation screenshots
> > (https://screenshot.googleplex.com/7d298sSr6JkqhaJ)
> >
> > Bug: 1307303
> > Change-Id: Ibd32bbfd1bd07ffcf06bd6240726d039025237cb
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3575382
> > Reviewed-by: Denis Kuznetsov <antrim@chromium.org>
> > Commit-Queue: Sherri Lin <sherrilin@google.com>
> > Cr-Commit-Position: refs/heads/main@{#992770}
>
> Bug: 1307303
> Change-Id: I27857e41c9003dc3205c9b5e88bac8c069ffce16
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3599039
> Reviewed-by: Denis Kuznetsov <antrim@chromium.org>
> Commit-Queue: Sherri Lin <sherrilin@google.com>
> Cr-Commit-Position: refs/heads/main@{#995310}

Bug: 1307303
Change-Id: I0e667fec7888c23239f4f779354af859d146c7bb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3603301
Reviewed-by: Denis Kuznetsov <antrim@chromium.org>
Commit-Queue: Sherri Lin <sherrilin@google.com>
Cr-Commit-Position: refs/heads/main@{#996051}

ash/BUILD.gn

@@ -635,6 +635,8 @@ component("ash") {
     "login/ui/hover_notifier.h",
     "login/ui/image_parser.cc",
     "login/ui/image_parser.h",
+    "login/ui/kiosk_app_default_message.cc",
+    "login/ui/kiosk_app_default_message.h",
     "login/ui/lock_contents_view.cc",
     "login/ui/lock_contents_view.h",
     "login/ui/lock_debug_view.cc",

ash/ash_strings.grd

@@ -4191,6 +4191,9 @@ Here are some things you can try to get started.
       <message name="IDS_SHELF_KIOSK_APP_INSTRUCTION" desc="Instructions to show users where to start using kiosk apps.">
         Open an app to get started
       </message>
+      <message name="IDS_SHELF_KIOSK_APP_SETUP" desc="Notifying users to ask their admins to setup the kiosk app.">
+        Ask your administrator to set up this device in the Google Admin console
+      </message>
       <message name="IDS_APP_ACCESSIBILITY_BLOCKED_INSTALLED_APP_ANNOUNCEMENT" desc="Accessibility text to specify a search result is a blocked installed app.">
         <ph name="APP_NAME">$1<ex>Files</ex></ph>, Installed App, Blocked
       </message>

ash/ash_strings_grd/IDS_SHELF_KIOSK_APP_SETUP.png.sha1

@@ -0,0 +1 @@
+a8c2ee402f4660daac50ec1a3a0e57900a56b9a3

ash/login/ui/kiosk_app_default_message.cc

@@ -0,0 +1,106 @@
+// Copyright 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ash/login/ui/kiosk_app_default_message.h"
+
+#include "ash/public/cpp/shell_window_ids.h"
+#include "ash/shell.h"
+#include "ash/strings/grit/ash_strings.h"
+#include "ash/style/ash_color_provider.h"
+#include "ash/system/tray/tray_popup_utils.h"
+#include "ash/system/tray/tray_utils.h"
+#include "components/vector_icons/vector_icons.h"
+#include "third_party/skia/include/core/SkColor.h"
+#include "ui/base/l10n/l10n_util.h"
+#include "ui/base/models/image_model.h"
+#include "ui/gfx/geometry/size.h"
+#include "ui/gfx/image/image_skia_operations.h"
+#include "ui/gfx/paint_vector_icon.h"
+#include "ui/gfx/vector_icon_types.h"
+#include "ui/views/controls/image_view.h"
+#include "ui/views/controls/label.h"
+#include "ui/views/layout/flex_layout.h"
+#include "ui/views/layout/layout_provider.h"
+#include "ui/views/widget/widget.h"
+
+namespace ash {
+namespace {
+
+// The icon size of the kiosk app message.
+constexpr int kIconSize = 16;
+
+// The line height of the kiosk app message title.
+constexpr int kTitleLineHeight = 20;
+
+}  // namespace
+
+KioskAppDefaultMessage::KioskAppDefaultMessage()
+    : BubbleDialogDelegateView(nullptr, views::BubbleBorder::NONE),
+      background_animator_(
+          /* Don't pass the Shelf so the translucent color is always used. */
+          nullptr,
+          Shell::Get()->wallpaper_controller()) {
+  auto* layout_provider = views::LayoutProvider::Get();
+  set_margins(gfx::Insets(layout_provider->GetDistanceMetric(
+      views::DISTANCE_DIALOG_CONTENT_MARGIN_TOP_CONTROL)));
+  SetShowCloseButton(false);
+  SetButtons(ui::DIALOG_BUTTON_NONE);
+  // Bubbles that use transparent colors should not paint their ClientViews to a
+  // layer as doing so could result in visual artifacts.
+  SetPaintClientToLayer(false);
+  background_animator_.Init(ShelfBackgroundType::kDefaultBg);
+  background_animator_observation_.Observe(&background_animator_);
+
+  views::FlexLayout* layout =
+      SetLayoutManager(std::make_unique<views::FlexLayout>());
+  layout->SetOrientation(views::LayoutOrientation::kHorizontal);
+  layout->SetMainAxisAlignment(views::LayoutAlignment::kCenter);
+  layout->SetCrossAxisAlignment(views::LayoutAlignment::kCenter);
+
+  // Set up the icon.
+  icon_ = AddChildView(std::make_unique<views::ImageView>());
+  icon_->SetProperty(
+      views::kMarginsKey,
+      gfx::Insets::TLBR(/*top=*/0, /*left=*/0, /*bottom=*/0,
+                        layout_provider->GetDistanceMetric(
+                            views::DISTANCE_RELATED_CONTROL_HORIZONTAL)));
+
+  // Set up the title view.
+  title_ = AddChildView(std::make_unique<views::Label>());
+  title_->SetText(l10n_util::GetStringUTF16(IDS_SHELF_KIOSK_APP_SETUP));
+  title_->SetLineHeight(kTitleLineHeight);
+  title_->SetMultiLine(true);
+  TrayPopupUtils::SetLabelFontList(title_,
+                                   TrayPopupUtils::FontStyle::kSmallTitle);
+
+  views::DialogDelegate::CreateDialogWidget(
+      this, nullptr /* context */,
+      Shell::GetContainer(ash::Shell::GetRootWindowForNewWindows(),
+                          kShellWindowId_SettingBubbleContainer) /* parent */);
+
+  GetBubbleFrameView()->SetCornerRadius(
+      views::LayoutProvider::Get()->GetCornerRadiusMetric(
+          views::Emphasis::kHigh));
+  GetBubbleFrameView()->SetBackgroundColor(
+      AshColorProvider::Get()->GetBaseLayerColor(
+          AshColorProvider::BaseLayerType::kTransparent90));
+}
+
+KioskAppDefaultMessage::~KioskAppDefaultMessage() = default;
+
+void KioskAppDefaultMessage::OnThemeChanged() {
+  views::View::OnThemeChanged();
+  auto* color_provider = AshColorProvider::Get();
+
+  SkColor icon_color = color_provider->GetContentLayerColor(
+      AshColorProvider::ContentLayerType::kButtonIconColor);
+  icon_->SetImage(gfx::CreateVectorIcon(vector_icons::kErrorOutlineIcon,
+                                        kIconSize, icon_color));
+
+  SkColor label_color = color_provider->GetContentLayerColor(
+      AshColorProvider::ContentLayerType::kTextColorPrimary);
+  title_->SetEnabledColor(label_color);
+}
+
+}  // namespace ash

ash/login/ui/kiosk_app_default_message.h

@@ -0,0 +1,48 @@
+// Copyright 2022 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ASH_LOGIN_UI_KIOSK_APP_DEFAULT_MESSAGE_H_
+#define ASH_LOGIN_UI_KIOSK_APP_DEFAULT_MESSAGE_H_
+
+#include "ash/ash_export.h"
+#include "ash/shelf/shelf_background_animator.h"
+#include "ash/shelf/shelf_background_animator_observer.h"
+#include "base/scoped_observation.h"
+#include "ui/views/bubble/bubble_dialog_delegate_view.h"
+
+namespace views {
+class ImageView;
+class Label;
+}  // namespace views
+
+namespace ash {
+
+// The implementation of kiosk app default message for the shelf.
+// KioskAppDefaultMessage is owned by itself and would be destroyed when its
+// widget got destroyed, which happened when the widget's window got destroyed.
+class ASH_EXPORT KioskAppDefaultMessage
+    : public views::BubbleDialogDelegateView,
+      public ShelfBackgroundAnimatorObserver {
+ public:
+  KioskAppDefaultMessage();
+  KioskAppDefaultMessage(const KioskAppDefaultMessage&) = delete;
+  KioskAppDefaultMessage& operator=(const KioskAppDefaultMessage&) = delete;
+  ~KioskAppDefaultMessage() override;
+
+  // views::View:
+  void OnThemeChanged() override;
+
+ private:
+  views::ImageView* icon_ = nullptr;
+  views::Label* title_ = nullptr;
+
+  ShelfBackgroundAnimator background_animator_;
+  base::ScopedObservation<ShelfBackgroundAnimator,
+                          ShelfBackgroundAnimatorObserver>
+      background_animator_observation_{this};
+};
+
+}  // namespace ash
+
+#endif  // ASH_LOGIN_UI_KIOSK_APP_DEFAULT_MESSAGE_H_

ash/login/ui/lock_contents_view.cc

@@ -18,6 +18,7 @@
 #include "ash/ime/ime_controller_impl.h"
 #include "ash/login/login_screen_controller.h"
 #include "ash/login/ui/bottom_status_indicator.h"
+#include "ash/login/ui/kiosk_app_default_message.h"
 #include "ash/login/ui/lock_screen.h"
 #include "ash/login/ui/lock_screen_media_controls_view.h"
 #include "ash/login/ui/login_auth_user_view.h"
@@ -327,7 +328,7 @@ class UserAddingScreenIndicator : public views::View {
     layout_manager->set_cross_axis_alignment(
         views::BoxLayout::CrossAxisAlignment::kStart);
 
-    info_icon_ = AddChildView(new views::ImageView());
+    info_icon_ = AddChildView(std::make_unique<views::ImageView>());
     info_icon_->SetPreferredSize(gfx::Size(kInfoIconSizeDp, kInfoIconSizeDp));
 
     std::u16string message =
@@ -434,6 +435,11 @@ LockContentsView::TestApi::TestApi(LockContentsView* view) : view_(view) {}
 
 LockContentsView::TestApi::~TestApi() = default;
 
+KioskAppDefaultMessage* LockContentsView::TestApi::kiosk_default_message()
+    const {
+  return view_->kiosk_default_message_;
+}
+
 LoginBigUserView* LockContentsView::TestApi::primary_big_view() const {
   return view_->primary_big_view_;
 }
@@ -671,12 +677,11 @@ LockContentsView::LockContentsView(
   tooltip_bubble_->SetPadding(kHorizontalPaddingLoginTooltipViewDp,
                               kVerticalPaddingLoginTooltipViewDp);
 
-  management_bubble_ = new ManagementBubble(
+  management_bubble_ = AddChildView(std::make_unique<ManagementBubble>(
       l10n_util::GetStringFUTF16(IDS_ASH_LOGIN_ENTERPRISE_MANAGED_POP_UP,
                                  ui::GetChromeOSDeviceName(),
                                  base::UTF8ToUTF16(enterprise_domain_manager)),
-      bottom_status_indicator_);
-  AddChildView(management_bubble_);
+      bottom_status_indicator_));
 
   warning_banner_bubble_ = AddChildView(std::make_unique<LoginErrorBubble>());
   warning_banner_bubble_->set_persistent(true);
@@ -688,7 +693,6 @@ LockContentsView::LockContentsView(
     user_adding_screen_indicator_ =
         AddChildView(std::make_unique<UserAddingScreenIndicator>());
   }
-
   OnLockScreenNoteStateChanged(initial_note_action_state);
   chromeos::PowerManagerClient::Get()->AddObserver(this);
   RegisterAccelerators();
@@ -833,6 +837,26 @@ void LockContentsView::ShowParentAccessDialog() {
   Shell::Get()->login_screen_controller()->ShowParentAccessButton(false);
 }
 
+void LockContentsView::SetKioskAppsButtonPresence(
+    bool is_kiosk_apps_button_present) {
+  if (!kiosk_license_mode_)
+    return;
+
+  // check if the kiosk app button is visible
+  if (is_kiosk_apps_button_present) {
+    if (kiosk_default_message_)
+      kiosk_default_message_->GetWidget()->Hide();
+  } else {
+    if (!kiosk_default_message_) {
+      // KioskAppDefaultMessage is owned by itself and would be destroyed when
+      // its widget got destroyed, which happened when the widget's window got
+      // destroyed.
+      kiosk_default_message_ = new KioskAppDefaultMessage();
+    }
+    kiosk_default_message_->GetWidget()->Show();
+  }
+}
+
 void LockContentsView::Layout() {
   View::Layout();
   LayoutTopHeader();
@@ -939,8 +963,7 @@ void LockContentsView::OnUsersChanged(const std::vector<LoginUserInfo>& users) {
       views::BoxLayout::CrossAxisAlignment::kCenter);
 
   // TODO(crbug.com/1307303): Determine if this is a kiosk license device.
-  bool kiosk_license_mode = false;
-  if (kiosk_license_mode)
+  if (kiosk_license_mode_)
     return;
 
   // If there are no users, show GAIA signin if login.
@@ -2563,6 +2586,11 @@ void LockContentsView::OnBackToSigninButtonTapped() {
       /*prefilled_account=*/EmptyAccountId());
 }
 
+void LockContentsView::SetKioskLicenseModeForTesting(
+    bool is_kiosk_license_mode) {
+  kiosk_license_mode_ = is_kiosk_license_mode;
+}
+
 BEGIN_METADATA(LockContentsView, NonAccessibleView)
 END_METADATA
 

ash/login/ui/lock_contents_view.h

@@ -46,6 +46,7 @@ class BoxLayout;
 
 namespace ash {
 
+class KioskAppDefaultMessage;
 class LockScreenMediaControlsView;
 class LoginAuthUserView;
 class LoginBigUserView;
@@ -89,6 +90,7 @@ class ASH_EXPORT LockContentsView
     explicit TestApi(LockContentsView* view);
     ~TestApi();
 
+    KioskAppDefaultMessage* kiosk_default_message() const;
     LoginBigUserView* primary_big_view() const;
     LoginBigUserView* opt_secondary_big_view() const;
     AccountId focused_user() const;
@@ -152,6 +154,7 @@ class ASH_EXPORT LockContentsView
   void ShowAdbEnabled();
   void ToggleSystemInfo();
   void ShowParentAccessDialog();
+  void SetKioskAppsButtonPresence(bool is_kiosk_apps_button_present);
 
   // views::View:
   void Layout() override;
@@ -253,6 +256,9 @@ class ASH_EXPORT LockContentsView
   // Called for debugging to remove forced online sign-in form |user|.
   void UndoForceOnlineSignInForUserForDebug(const AccountId& user);
 
+  // Test API. Set device to have kiosk license.
+  void SetKioskLicenseModeForTesting(bool is_kiosk_license_mode);
+
   // Called by LockScreenMediaControlsView.
   void CreateMediaControlsLayout();
   void HideMediaControlsLayout();
@@ -487,6 +493,10 @@ class ASH_EXPORT LockContentsView
   // Contains authentication user and the additional user views.
   NonAccessibleView* main_view_ = nullptr;
 
+  // If the kiosk app button is not visible, the kiosk app default message would
+  // be shown.
+  raw_ptr<KioskAppDefaultMessage> kiosk_default_message_ = nullptr;
+
   // Actions that should be executed before a new layout happens caused by a
   // display change (eg. screen rotation). A full layout pass is performed after
   // all actions are executed.
@@ -532,6 +542,10 @@ class ASH_EXPORT LockContentsView
   // screen note state.
   bool disable_lock_screen_note_ = false;
 
+  // TODO(1307303): Change it to the real function that checks if device is with
+  // Kiosk License
+  bool kiosk_license_mode_ = false;
+
   // Whether the system information should be displayed or not be displayed
   // forcedly according to policy settings.
   absl::optional<bool> enable_system_info_enforced_ = absl::nullopt;

ash/login/ui/lock_contents_view_unittest.cc

@@ -17,6 +17,7 @@
 #include "ash/login/mock_login_screen_client.h"
 #include "ash/login/ui/arrow_button_view.h"
 #include "ash/login/ui/fake_login_detachable_base_model.h"
+#include "ash/login/ui/kiosk_app_default_message.h"
 #include "ash/login/ui/lock_screen.h"
 #include "ash/login/ui/lock_screen_media_controls_view.h"
 #include "ash/login/ui/login_auth_user_view.h"
@@ -35,6 +36,7 @@
 #include "ash/public/mojom/tray_action.mojom.h"
 #include "ash/root_window_controller.h"
 #include "ash/session/session_controller_impl.h"
+#include "ash/shelf/login_shelf_view.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shelf/shelf_navigation_widget.h"
 #include "ash/shelf/shelf_widget.h"
@@ -3228,4 +3230,156 @@ TEST_F(LockContentsViewUnitTest, SmartLockStateHidesAuthErrorMessage) {
   EXPECT_FALSE(test_api.auth_error_bubble()->GetVisible());
 }
 
+class LockContentsViewWithKioskLicenseTest : public LoginTestBase {
+ protected:
+  LockContentsViewWithKioskLicenseTest() = default;
+  LockContentsViewWithKioskLicenseTest(LockContentsViewWithKioskLicenseTest&) =
+      delete;
+  LockContentsViewWithKioskLicenseTest& operator=(
+      LockContentsViewWithKioskLicenseTest&) = delete;
+  ~LockContentsViewWithKioskLicenseTest() override = default;
+
+  void SetUp() override {
+    set_start_session(false);
+    LoginTestBase::SetUp();
+    login_shelf_view_ = GetPrimaryShelf()->shelf_widget()->login_shelf_view();
+    // Set initial states.
+    NotifySessionStateChanged(session_manager::SessionState::OOBE);
+  }
+
+  void SetNumberOfKioskApps(int number_apps) {
+    std::vector<KioskAppMenuEntry> kiosk_apps(number_apps);
+    login_shelf_view_->SetKioskApps(kiosk_apps);
+  }
+
+  void NotifySessionStateChanged(session_manager::SessionState state) {
+    GetSessionControllerClient()->SetSessionState(state);
+    GetSessionControllerClient()->FlushForTest();
+  }
+
+  LoginShelfView* login_shelf_view_ = nullptr;  // Unowned.
+};
+
+// Checks default message hides if device is with kiosk license but with apps.
+TEST_F(LockContentsViewWithKioskLicenseTest,
+       ShouldNotShowKioskDefaultMessageWithApps) {
+  // Set up
+  const bool is_kiosk_license_mode = true;
+  login_shelf_view_->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  // Show login screen with no user.
+  ASSERT_NO_FATAL_FAILURE(ShowLoginScreen());
+  LockContentsView* lock_contents_view =
+      LockScreen::TestApi(LockScreen::Get()).contents_view();
+  lock_contents_view->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  LockContentsView::TestApi test_api(lock_contents_view);
+  SetUserCount(0);
+  std::unique_ptr<views::Widget> widget =
+      CreateWidgetWithContent(lock_contents_view);
+
+  NotifySessionStateChanged(session_manager::SessionState::LOGIN_PRIMARY);
+  SetNumberOfKioskApps(1);
+
+  EXPECT_FALSE(test_api.kiosk_default_message());
+}
+
+// Checks default message hidden if device is not with kiosk license and has
+// no apps.
+TEST_F(LockContentsViewWithKioskLicenseTest, ShouldHideKioskDefaultMessage) {
+  // Set up
+  const bool is_kiosk_license_mode = false;
+  login_shelf_view_->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  // Show login screen with no user.
+  ASSERT_NO_FATAL_FAILURE(ShowLoginScreen());
+  LockContentsView* lock_contents_view =
+      LockScreen::TestApi(LockScreen::Get()).contents_view();
+  lock_contents_view->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  LockContentsView::TestApi test_api(lock_contents_view);
+  SetUserCount(0);
+  std::unique_ptr<views::Widget> widget =
+      CreateWidgetWithContent(lock_contents_view);
+
+  NotifySessionStateChanged(session_manager::SessionState::LOGIN_PRIMARY);
+  SetNumberOfKioskApps(0);
+
+  EXPECT_FALSE(test_api.kiosk_default_message());
+}
+
+// Checks default message appeared if device is with kiosk license and no
+// kiosk app is set up.
+TEST_F(LockContentsViewWithKioskLicenseTest,
+       ShouldShowKioskDefaultMessageWithoutApps) {
+  // Set up
+  const bool is_kiosk_license_mode = true;
+  login_shelf_view_->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  // Show login screen with no user.
+  ASSERT_NO_FATAL_FAILURE(ShowLoginScreen());
+  LockContentsView* lock_contents_view =
+      LockScreen::TestApi(LockScreen::Get()).contents_view();
+  lock_contents_view->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  LockContentsView::TestApi test_api(lock_contents_view);
+  SetUserCount(0);
+  std::unique_ptr<views::Widget> widget =
+      CreateWidgetWithContent(lock_contents_view);
+
+  NotifySessionStateChanged(session_manager::SessionState::LOGIN_PRIMARY);
+  SetNumberOfKioskApps(0);
+
+  EXPECT_TRUE(test_api.kiosk_default_message());
+  EXPECT_TRUE(test_api.kiosk_default_message()->GetWidget()->IsVisible());
+}
+
+// Checks default message appeared if device is with kiosk license, no
+// kiosk app is set up and has users.
+TEST_F(LockContentsViewWithKioskLicenseTest,
+       ShouldShowKioskDefaultMessageWithoutAppsWithUsers) {
+  // Set up
+  const bool is_kiosk_license_mode = true;
+  login_shelf_view_->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  // Show login screen with one user.
+  ASSERT_NO_FATAL_FAILURE(ShowLoginScreen());
+  LockContentsView* lock_contents_view =
+      LockScreen::TestApi(LockScreen::Get()).contents_view();
+  lock_contents_view->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  LockContentsView::TestApi test_api(lock_contents_view);
+  SetUserCount(1);
+  std::unique_ptr<views::Widget> widget =
+      CreateWidgetWithContent(lock_contents_view);
+
+  NotifySessionStateChanged(session_manager::SessionState::LOGIN_PRIMARY);
+  SetNumberOfKioskApps(0);
+
+  EXPECT_TRUE(test_api.kiosk_default_message());
+  EXPECT_TRUE(test_api.kiosk_default_message()->GetWidget()->IsVisible());
+}
+
+// Checks default message appeared if device is with kiosk license and no
+// kiosk app is set up. After some kiosk app is set up, the default message
+// shall disappear.
+TEST_F(LockContentsViewWithKioskLicenseTest,
+       ShouldShowAndHideKioskDefaultMessageWithAppChanges) {
+  // Set up
+  const bool is_kiosk_license_mode = true;
+  login_shelf_view_->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  // Show login screen with no user.
+  ASSERT_NO_FATAL_FAILURE(ShowLoginScreen());
+  LockContentsView* lock_contents_view =
+      LockScreen::TestApi(LockScreen::Get()).contents_view();
+  lock_contents_view->SetKioskLicenseModeForTesting(is_kiosk_license_mode);
+  LockContentsView::TestApi test_api(lock_contents_view);
+  SetUserCount(0);
+  std::unique_ptr<views::Widget> widget =
+      CreateWidgetWithContent(lock_contents_view);
+
+  NotifySessionStateChanged(session_manager::SessionState::LOGIN_PRIMARY);
+  SetNumberOfKioskApps(0);
+
+  EXPECT_TRUE(test_api.kiosk_default_message());
+  EXPECT_TRUE(test_api.kiosk_default_message()->GetWidget()->IsVisible());
+
+  SetNumberOfKioskApps(1);
+
+  EXPECT_TRUE(test_api.kiosk_default_message());
+  EXPECT_FALSE(test_api.kiosk_default_message()->GetWidget()->IsVisible());
+}
+
 }  // namespace ash

ash/login/ui/lock_screen.cc

@@ -165,6 +165,10 @@ void LockScreen::ShowParentAccessDialog() {
   contents_view_->ShowParentAccessDialog();
 }
 
+void LockScreen::SetKioskAppsButtonPresence(bool is_kiosk_apps_button_present) {
+  contents_view_->SetKioskAppsButtonPresence(is_kiosk_apps_button_present);
+}
+
 void LockScreen::OnLockScreenNoteStateChanged(mojom::TrayActionState state) {
   Shell::Get()
       ->login_screen_controller()

ash/login/ui/lock_screen.h

@@ -72,6 +72,7 @@ class ASH_EXPORT LockScreen : public TrayActionObserver,
   void FocusNextUser();
   void FocusPreviousUser();
   void ShowParentAccessDialog();
+  void SetKioskAppsButtonPresence(bool has_kiosk_apps);
 
   // TrayActionObserver:
   void OnLockScreenNoteStateChanged(mojom::TrayActionState state) override;

ash/shelf/login_shelf_view.cc

@@ -731,6 +731,10 @@ void LoginShelfView::SetKioskApps(
     const std::vector<KioskAppMenuEntry>& kiosk_apps) {
   kiosk_apps_button_->SetApps(kiosk_apps);
   UpdateUi();
+  if (LockScreen::HasInstance()) {
+    LockScreen::Get()->SetKioskAppsButtonPresence(
+        kiosk_apps_button_->GetVisible());
+  }
 }
 
 void LoginShelfView::ConfigureKioskCallbacks(