Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

99 files changed, 5755 insertions, 0 deletions

diff --git a/toolkit/mozapps/update/tests/browser/browser.bits.ini b/toolkit/mozapps/update/tests/browser/browser.bits.ini
new file mode 100644
index 0000000000..02dde57751
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser.bits.ini
@@ -0,0 +1,81 @@
+[DEFAULT]
+skip-if =
+  os != 'win'
+  msix # Updater is disabled in MSIX builds
+reason = BITS is only available on Windows.
+dupe-manifest =
+tags = appupdate bits
+head = head.js
+support-files =
+  ../data/shared.js
+  ../data/sharedUpdateXML.js
+  ../data/app_update.sjs
+  downloadPage.html
+  testConstants.js
+
+prefs =
+  app.update.BITS.enabled=true
+  app.update.langpack.enabled=true
+
+# BITS Download Tests
+#####################
+
+# About Dialog Application Update Tests
+[browser_aboutDialog_bc_downloaded.js]
+[browser_aboutDialog_bc_downloaded_staged.js]
+[browser_aboutDialog_bc_downloaded_staging.js]
+[browser_aboutDialog_bc_downloaded_stagingFailure.js]
+[browser_aboutDialog_bc_downloading.js]
+[browser_aboutDialog_bc_downloading_notify.js]
+[browser_aboutDialog_bc_downloading_staging.js]
+[browser_aboutDialog_bc_multiUpdate.js]
+[browser_aboutDialog_fc_downloadAuto.js]
+[browser_aboutDialog_fc_downloadAuto_staging.js]
+[browser_aboutDialog_fc_downloadOptIn.js]
+[browser_aboutDialog_fc_downloadOptIn_staging.js]
+[browser_aboutDialog_fc_patch_completeBadSize.js]
+[browser_aboutDialog_fc_patch_partialBadSize.js]
+[browser_aboutDialog_fc_patch_partialBadSize_complete.js]
+[browser_aboutDialog_fc_patch_partialBadSize_completeBadSize.js]
+
+# about:preferences Application Update Tests
+[browser_aboutPrefs_bc_downloaded.js]
+[browser_aboutPrefs_bc_downloaded_staged.js]
+[browser_aboutPrefs_bc_downloaded_staging.js]
+[browser_aboutPrefs_bc_downloaded_stagingFailure.js]
+[browser_aboutPrefs_bc_downloading.js]
+[browser_aboutPrefs_bc_downloading_staging.js]
+[browser_aboutPrefs_bc_multiUpdate.js]
+[browser_aboutPrefs_fc_downloadAuto.js]
+[browser_aboutPrefs_fc_downloadAuto_staging.js]
+[browser_aboutPrefs_fc_downloadOptIn.js]
+[browser_aboutPrefs_fc_downloadOptIn_staging.js]
+[browser_aboutPrefs_fc_patch_completeBadSize.js]
+[browser_aboutPrefs_fc_patch_partialBadSize.js]
+[browser_aboutPrefs_fc_patch_partialBadSize_complete.js]
+[browser_aboutPrefs_fc_patch_partialBadSize_completeBadSize.js]
+
+# Doorhanger Application Update Tests
+[browser_doorhanger_bc_downloadAutoFailures.js]
+[browser_doorhanger_bc_downloadAutoFailures_bgWin.js]
+[browser_doorhanger_bc_downloadOptIn.js]
+[browser_doorhanger_bc_downloadOptIn_bgWin.js]
+[browser_doorhanger_bc_downloadOptIn_staging.js]
+[browser_doorhanger_bc_downloaded.js]
+[browser_doorhanger_bc_downloaded_disableBITS.js]
+[browser_doorhanger_bc_downloaded_staged.js]
+[browser_doorhanger_bc_multiUpdate.js]
+[browser_doorhanger_bc_multiUpdate_promptWaitTime.js]
+[browser_doorhanger_bc_patch_completeBadSize.js]
+[browser_doorhanger_bc_patch_partialBadSize.js]
+[browser_doorhanger_bc_patch_partialBadSize_complete.js]
+[browser_doorhanger_bc_patch_partialBadSize_completeBadSize.js]
+[browser_doorhanger_sp_patch_completeApplyFailure.js]
+[browser_doorhanger_sp_patch_partialApplyFailure.js]
+[browser_doorhanger_sp_patch_partialApplyFailure_complete.js]
+[browser_doorhanger_sp_patch_partialApplyFailure_completeBadSize.js]
+[browser_doorhanger_sp_patch_partialApplyFailure_complete_staging.js]
+
+# Telemetry Update Ping Tests
+[browser_telemetry_updatePing_downloaded_ready.js]
+[browser_telemetry_updatePing_staged_ready.js]
diff --git a/toolkit/mozapps/update/tests/browser/browser.ini b/toolkit/mozapps/update/tests/browser/browser.ini
new file mode 100644
index 0000000000..f2d7313c94
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser.ini
@@ -0,0 +1,122 @@
+[DEFAULT]
+dupe-manifest =
+tags = appupdate internal
+head = head.js
+support-files =
+  ../data/shared.js
+  ../data/sharedUpdateXML.js
+  ../data/app_update.sjs
+  downloadPage.html
+  testConstants.js
+prefs =
+  app.update.BITS.enabled=false
+  app.update.langpack.enabled=true
+skip-if = os == 'win' && msix # Updater is disabled in MSIX builds
+
+# About Dialog Application Update Tests
+[browser_aboutDialog_AppUpdater_stop_checking.js]
+[browser_aboutDialog_AppUpdater_stop_download_and_install.js]
+[browser_aboutDialog_AppUpdater_stop_download_failed.js]
+[browser_aboutDialog_AppUpdater_stop_downloading.js]
+[browser_aboutDialog_AppUpdater_stop_internal_error.js]
+[browser_aboutDialog_AppUpdater_stop_no_update.js]
+[browser_aboutDialog_AppUpdater_stop_ready_for_restart.js]
+[browser_aboutDialog_AppUpdater_stop_staging.js]
+[browser_aboutDialog_AppUpdater_stop_swap.js]
+[browser_aboutDialog_bc_downloaded.js]
+[browser_aboutDialog_bc_downloaded_staged.js]
+[browser_aboutDialog_bc_downloaded_staging.js]
+[browser_aboutDialog_bc_downloaded_stagingFailure.js]
+[browser_aboutDialog_bc_downloading.js]
+[browser_aboutDialog_bc_downloading_notify.js]
+[browser_aboutDialog_bc_downloading_staging.js]
+[browser_aboutDialog_bc_multiUpdate.js]
+[browser_aboutDialog_fc_apply_blocked.js]
+[browser_aboutDialog_fc_check_cantApply.js]
+skip-if = os != 'win'
+reason = test must be able to prevent file deletion.
+[browser_aboutDialog_fc_check_malformedXML.js]
+[browser_aboutDialog_fc_check_noUpdate.js]
+[browser_aboutDialog_fc_check_otherInstance.js]
+skip-if = os != 'win'
+reason = Windows only feature.
+[browser_aboutDialog_fc_check_unsupported.js]
+[browser_aboutDialog_fc_downloadAuto.js]
+skip-if = tsan # Bug 1683730
+[browser_aboutDialog_fc_downloadAuto_staging.js]
+[browser_aboutDialog_fc_downloadOptIn.js]
+[browser_aboutDialog_fc_downloadOptIn_staging.js]
+[browser_aboutDialog_fc_network_failure.js]
+[browser_aboutDialog_fc_network_offline.js]
+[browser_aboutDialog_fc_patch_completeBadSize.js]
+[browser_aboutDialog_fc_patch_partialBadSize.js]
+[browser_aboutDialog_fc_patch_partialBadSize_complete.js]
+[browser_aboutDialog_fc_patch_partialBadSize_completeBadSize.js]
+[browser_aboutDialog_internalError.js]
+[browser_aboutPrefs_backgroundUpdateSetting.js]
+[browser_aboutPrefs_bc_downloaded.js]
+[browser_aboutPrefs_bc_downloaded_staged.js]
+[browser_aboutPrefs_bc_downloaded_staging.js]
+[browser_aboutPrefs_bc_downloaded_stagingFailure.js]
+
+# about:preferences Application Update Tests
+[browser_aboutPrefs_bc_downloading.js]
+[browser_aboutPrefs_bc_downloading_staging.js]
+[browser_aboutPrefs_bc_multiUpdate.js]
+[browser_aboutPrefs_fc_apply_blocked.js]
+[browser_aboutPrefs_fc_check_cantApply.js]
+skip-if = os != 'win'
+reason = test must be able to prevent file deletion.
+[browser_aboutPrefs_fc_check_malformedXML.js]
+[browser_aboutPrefs_fc_check_noUpdate.js]
+[browser_aboutPrefs_fc_check_otherInstance.js]
+skip-if = os != 'win'
+reason = Windows only feature.
+[browser_aboutPrefs_fc_check_unsupported.js]
+[browser_aboutPrefs_fc_downloadAuto.js]
+[browser_aboutPrefs_fc_downloadAuto_staging.js]
+[browser_aboutPrefs_fc_downloadOptIn.js]
+[browser_aboutPrefs_fc_downloadOptIn_staging.js]
+[browser_aboutPrefs_fc_network_failure.js]
+[browser_aboutPrefs_fc_network_offline.js]
+[browser_aboutPrefs_fc_patch_completeBadSize.js]
+[browser_aboutPrefs_fc_patch_partialBadSize.js]
+[browser_aboutPrefs_fc_patch_partialBadSize_complete.js]
+[browser_aboutPrefs_fc_patch_partialBadSize_completeBadSize.js]
+[browser_aboutPrefs_internalError.js]
+[browser_aboutPrefs_settings.js]
+
+# Doorhanger Application Update Tests
+[browser_doorhanger_bc_check_cantApply.js]
+skip-if = os != 'win'
+reason = test must be able to prevent file deletion.
+[browser_doorhanger_bc_check_malformedXML.js]
+[browser_doorhanger_bc_check_unsupported.js]
+[browser_doorhanger_bc_downloadAutoFailures.js]
+[browser_doorhanger_bc_downloadAutoFailures_bgWin.js]
+[browser_doorhanger_bc_downloadOptIn.js]
+[browser_doorhanger_bc_downloadOptIn_bgWin.js]
+[browser_doorhanger_bc_downloadOptIn_staging.js]
+[browser_doorhanger_bc_downloaded.js]
+[browser_doorhanger_bc_downloaded_staged.js]
+[browser_doorhanger_bc_multiUpdate.js]
+[browser_doorhanger_bc_multiUpdate_promptWaitTime.js]
+[browser_doorhanger_bc_patch_completeBadSize.js]
+[browser_doorhanger_bc_patch_partialBadSize.js]
+[browser_doorhanger_bc_patch_partialBadSize_complete.js]
+[browser_doorhanger_bc_patch_partialBadSize_completeBadSize.js]
+[browser_doorhanger_sp_patch_completeApplyFailure.js]
+[browser_doorhanger_sp_patch_partialApplyFailure.js]
+[browser_doorhanger_sp_patch_partialApplyFailure_complete.js]
+[browser_doorhanger_sp_patch_partialApplyFailure_completeBadSize.js]
+[browser_doorhanger_sp_patch_partialApplyFailure_complete_staging.js]
+
+# Elevation Dialog Tests
+[browser_elevationDialog.js]
+
+# Memory Fallback Tests
+[browser_memory_allocation_error_fallback.js]
+
+# Telemetry Update Ping Tests
+[browser_telemetry_updatePing_downloaded_ready.js]
+[browser_telemetry_updatePing_staged_ready.js]
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_checking.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_checking.js
new file mode 100644
index 0000000000..370f658656
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_checking.js
@@ -0,0 +1,32 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that while a download is in-progress, calling `AppUpdater.stop()` while
+// in the checking state causes the interface to return to the `NEVER_CHECKED`
+// state.
+// This is less a test of the About dialog than of AppUpdater, but it's easier
+// to test it via the About dialog just because there is already a testing
+// framework for the About dialog.
+add_task(async function aboutDialog_AppUpdater_stop_checking() {
+  let params = { queryString: "&noUpdates=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      // Omit the continue file to keep us in the checking state.
+    },
+    aboutDialog => {
+      aboutDialog.gAppUpdater._appUpdater.stop();
+    },
+    {
+      panelId: "checkForUpdates",
+    },
+  ]);
+
+  // Ideally this would go in a cleanup function. But this needs to happen
+  // before any other cleanup functions and for some reason cleanup functions
+  // do not always seem to execute in reverse registration order.
+  dump("Cleanup: Waiting for checking to finish.\n");
+  await continueFileHandler(CONTINUE_CHECK);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_download_and_install.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_download_and_install.js
new file mode 100644
index 0000000000..74e179043d
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_download_and_install.js
@@ -0,0 +1,41 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that while a download is in-progress, calling `AppUpdater.stop()` while
+// in the "download and install" state causes the interface to return to the
+// `NEVER_CHECKED` state.
+// This is less a test of the About dialog than of AppUpdater, but it's easier
+// to test it via the About dialog just because there is already a testing
+// framework for the About dialog.
+add_task(async function aboutDialog_AppUpdater_stop_download_and_install() {
+  await UpdateUtils.setAppUpdateAutoEnabled(false);
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloadAndInstall",
+      noContinue: true,
+    },
+    aboutDialog => {
+      aboutDialog.gAppUpdater._appUpdater.stop();
+    },
+    {
+      panelId: "checkForUpdates",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_download_failed.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_download_failed.js
new file mode 100644
index 0000000000..8900765f81
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_download_failed.js
@@ -0,0 +1,43 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that while a download is in-progress, calling `AppUpdater.stop()` while
+// in the "downloadFailed" state doesn't cause a shift to any other state, such
+// as internal error.
+// This is less a test of the About dialog than of AppUpdater, but it's easier
+// to test it via the About dialog just because there is already a testing
+// framework for the About dialog.
+add_task(async function aboutDialog_AppUpdater_stop_download_failed() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "complete", bitsResult: gBadSizeResult };
+    downloadInfo[1] = { patchType: "complete", internalResult: gBadSizeResult };
+  } else {
+    downloadInfo[0] = { patchType: "complete", internalResult: gBadSizeResult };
+  }
+
+  let params = { queryString: "&completePatchOnly=1&invalidCompleteSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "downloadFailed",
+    },
+    aboutDialog => {
+      aboutDialog.gAppUpdater._appUpdater.stop();
+    },
+    {
+      panelId: "downloadFailed",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_downloading.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_downloading.js
new file mode 100644
index 0000000000..d0de7e03b9
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_downloading.js
@@ -0,0 +1,47 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that while a download is in-progress, calling `AppUpdater.stop()` during
+// the downloading state causes the interface to return to the `NEVER_CHECKED`
+// state.
+// This is less a test of the About dialog than of AppUpdater, but it's easier
+// to test it via the About dialog just because there is already a testing
+// framework for the About dialog.
+add_task(async function aboutDialog_AppUpdater_stop_downloading() {
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&useSlowDownloadMar=1&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_DOWNLOADING,
+  };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      // Omit continue file to keep the UI in the downloading state.
+    },
+    aboutDialog => {
+      aboutDialog.gAppUpdater._appUpdater.stop();
+    },
+    {
+      panelId: "checkForUpdates",
+      // The update will still be in the downloading state even though
+      // AppUpdater has stopped because stopping AppUpdater doesn't stop the
+      // Application Update Service from continuing with the update.
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      expectedStateOverride: Ci.nsIApplicationUpdateService.STATE_DOWNLOADING,
+    },
+  ]);
+
+  // Ideally this would go in a cleanup function. But this needs to happen
+  // before any other cleanup functions and for some reason cleanup functions
+  // do not always seem to execute in reverse registration order.
+  dump("Cleanup: Waiting for downloading to finish.\n");
+  await continueFileHandler(CONTINUE_DOWNLOAD);
+  if (gAUS.currentState == Ci.nsIApplicationUpdateService.STATE_DOWNLOADING) {
+    await gAUS.stateTransition;
+  }
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_internal_error.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_internal_error.js
new file mode 100644
index 0000000000..69c13783bf
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_internal_error.js
@@ -0,0 +1,45 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+ChromeUtils.defineESModuleGetters(this, {
+  AppUpdater: "resource://gre/modules/AppUpdater.sys.mjs",
+  sinon: "resource://testing-common/Sinon.sys.mjs",
+});
+
+add_setup(function setup_internalErrorTest() {
+  const sandbox = sinon.createSandbox();
+  sandbox.stub(AppUpdater.prototype, "aus").get(() => {
+    throw new Error("intentional test error");
+  });
+  sandbox.stub(AppUpdater.prototype, "checker").get(() => {
+    throw new Error("intentional test error");
+  });
+  sandbox.stub(AppUpdater.prototype, "um").get(() => {
+    throw new Error("intentional test error");
+  });
+  registerCleanupFunction(() => {
+    sandbox.restore();
+  });
+});
+
+// Test that while a download is in-progress, calling `AppUpdater.stop()` while
+// in the "internal error" state doesn't cause a shift to any other state.
+// This is less a test of the About dialog than of AppUpdater, but it's easier
+// to test it via the About dialog just because there is already a testing
+// framework for the About dialog.
+add_task(async function aboutDialog_AppUpdater_stop_internal_error() {
+  let params = {};
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "internalError",
+    },
+    aboutDialog => {
+      aboutDialog.gAppUpdater._appUpdater.stop();
+    },
+    {
+      panelId: "internalError",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_no_update.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_no_update.js
new file mode 100644
index 0000000000..65a52ccc87
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_no_update.js
@@ -0,0 +1,29 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that while a download is in-progress, calling `AppUpdater.stop()` while
+// in the "noUpdatesFound" state doesn't cause a shift to any other state, such
+// as internal error.
+// This is less a test of the About dialog than of AppUpdater, but it's easier
+// to test it via the About dialog just because there is already a testing
+// framework for the About dialog.
+add_task(async function aboutDialog_AppUpdater_stop_no_update() {
+  let params = { queryString: "&noUpdates=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "noUpdatesFound",
+    },
+    aboutDialog => {
+      aboutDialog.gAppUpdater._appUpdater.stop();
+    },
+    {
+      panelId: "noUpdatesFound",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_ready_for_restart.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_ready_for_restart.js
new file mode 100644
index 0000000000..8c9d1f788f
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_ready_for_restart.js
@@ -0,0 +1,27 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that while a download is in-progress, calling `AppUpdater.stop()` while
+// in the "ready for restart" state doesn't cause a shift to any other state,
+// such as internal error.
+// This is less a test of the About dialog than of AppUpdater, but it's easier
+// to test it via the About dialog just because there is already a testing
+// framework for the About dialog.
+add_task(async function aboutDialog_AppUpdater_stop_ready_for_restart() {
+  let params = { backgroundUpdate: true, waitForUpdateState: STATE_PENDING };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+    },
+    aboutDialog => {
+      aboutDialog.gAppUpdater._appUpdater.stop();
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_staging.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_staging.js
new file mode 100644
index 0000000000..dd822e6391
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_staging.js
@@ -0,0 +1,64 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test that while a download is in-progress, calling `AppUpdater.stop()` while
+// in the staging state causes the interface to return to the `NEVER_CHECKED`
+// state.
+// This is less a test of the About dialog than of AppUpdater, but it's easier
+// to test it via the About dialog just because there is already a testing
+// framework for the About dialog.
+add_task(async function aboutDialog_AppUpdater_stop_staging() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&useSlowDownloadMar=1&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_DOWNLOADING,
+  };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      // Don't pass a continue file in order to leave us in the staging state.
+    },
+    aboutDialog => {
+      aboutDialog.gAppUpdater._appUpdater.stop();
+    },
+    {
+      panelId: "checkForUpdates",
+      // The update will still be in the staging state even though AppUpdater
+      // has stopped because stopping AppUpdater doesn't stop the Application
+      // Update Service from continuing with the update.
+      checkActiveUpdate: { state: STATE_PENDING },
+      expectedStateOverride: Ci.nsIApplicationUpdateService.STATE_STAGING,
+    },
+  ]);
+
+  // Ideally this would go in a cleanup function. But this needs to happen
+  // before any other cleanup functions and for some reason cleanup functions
+  // do not always seem to execute in reverse registration order.
+  dump("Cleanup: Waiting for staging to finish.\n");
+  await continueFileHandler(CONTINUE_STAGING);
+  if (gAUS.currentState == Ci.nsIApplicationUpdateService.STATE_STAGING) {
+    await gAUS.stateTransition;
+  }
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_swap.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_swap.js
new file mode 100644
index 0000000000..02441dea53
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_AppUpdater_stop_swap.js
@@ -0,0 +1,64 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const FIRST_UPDATE_VERSION = "999998.0";
+const SECOND_UPDATE_VERSION = "999999.0";
+
+function prepareToDownloadVersion(version) {
+  setUpdateURL(
+    URL_HTTP_UPDATE_SJS +
+      `?detailsURL=${gDetailsURL}&promptWaitTime=0&appVersion=${version}`
+  );
+}
+
+add_task(async function aboutDialog_backgroundCheck_multiUpdate() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let params = {
+    version: FIRST_UPDATE_VERSION,
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_PENDING,
+  };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+    () => {
+      prepareToDownloadVersion(SECOND_UPDATE_VERSION);
+      gAUS.checkForBackgroundUpdates();
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      // Don't pass a continue file in order to leave us in the staging state.
+    },
+    aboutDialog => {
+      aboutDialog.gAppUpdater._appUpdater.stop();
+    },
+    {
+      panelId: "checkForUpdates",
+      checkActiveUpdate: { state: STATE_PENDING },
+      expectedStateOverride: Ci.nsIApplicationUpdateService.STATE_STAGING,
+    },
+  ]);
+
+  // Ideally this would go in a cleanup function. But this needs to happen
+  // before any other cleanup functions and for some reason cleanup functions
+  // do not always seem to execute in reverse registration order.
+  dump("Cleanup: Waiting for staging to finish.\n");
+  await continueFileHandler(CONTINUE_STAGING);
+  if (gAUS.currentState == Ci.nsIApplicationUpdateService.STATE_STAGING) {
+    await gAUS.stateTransition;
+  }
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded.js
new file mode 100644
index 0000000000..0955750c93
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded.js
@@ -0,0 +1,17 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog background check for updates
+// with the update downloaded when the About Dialog is opened.
+add_task(async function aboutDialog_backgroundCheck_downloaded() {
+  let params = { backgroundUpdate: true, waitForUpdateState: STATE_PENDING };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded_staged.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded_staged.js
new file mode 100644
index 0000000000..2d7bd64d05
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded_staged.js
@@ -0,0 +1,28 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog background check for updates
+// with the update downloaded and staged when the About Dialog is opened.
+add_task(async function aboutDialog_backgroundCheck_downloaded_staged() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    continueFile: CONTINUE_STAGING,
+    waitForUpdateState: STATE_APPLIED,
+  };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded_staging.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded_staging.js
new file mode 100644
index 0000000000..b60a8f128d
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded_staging.js
@@ -0,0 +1,55 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog background check for updates
+// with the update downloaded and the About Dialog opened during staging.
+add_task(async function aboutDialog_backgroundCheck_downloaded_staging() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let lankpackCall = mockLangpackInstall();
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_PENDING,
+  };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    async aboutDialog => {
+      // Once the state is applied but langpacks aren't complete the about
+      // dialog should still be showing applying.
+      TestUtils.waitForCondition(() => {
+        return readStatusFile() == STATE_APPLIED;
+      });
+
+      is(
+        aboutDialog.gAppUpdater.selectedPanel.id,
+        "applying",
+        "UI should still show as applying."
+      );
+
+      let { appVersion, resolve } = await lankpackCall;
+      is(
+        appVersion,
+        Services.appinfo.version,
+        "Should see the right app version."
+      );
+      resolve();
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded_stagingFailure.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded_stagingFailure.js
new file mode 100644
index 0000000000..c05b2daa74
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloaded_stagingFailure.js
@@ -0,0 +1,31 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog background check for updates
+// with the update downloaded and staging has failed when the About Dialog is
+// opened.
+add_task(
+  async function aboutDialog_backgroundCheck_downloaded_stagingFailure() {
+    Services.env.set("MOZ_TEST_STAGING_ERROR", "1");
+    await SpecialPowers.pushPrefEnv({
+      set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+    });
+
+    // Since the partial should be successful specify an invalid size for the
+    // complete update.
+    let params = {
+      queryString: "&completePatchOnly=1",
+      backgroundUpdate: true,
+      waitForUpdateState: STATE_PENDING,
+    };
+    await runAboutDialogUpdateTest(params, [
+      {
+        panelId: "apply",
+        checkActiveUpdate: { state: STATE_PENDING },
+        continueFile: null,
+      },
+    ]);
+  }
+);
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloading.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloading.js
new file mode 100644
index 0000000000..6c2a7486a9
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloading.js
@@ -0,0 +1,76 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog background check for updates
+// with the About Dialog opened during downloading.
+add_task(async function aboutDialog_backgroundCheck_downloading() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_NOTIFYDURINGDOWNLOAD, false]],
+  });
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  let lankpackCall = mockLangpackInstall();
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&useSlowDownloadMar=1&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_DOWNLOADING,
+  };
+  await runAboutDialogUpdateTest(params, [
+    async function aboutDialog_downloading() {
+      is(
+        PanelUI.notificationPanel.state,
+        "closed",
+        "The window's doorhanger is closed."
+      );
+      ok(
+        !PanelUI.menuButton.hasAttribute("badge-status"),
+        "The window does not have a badge."
+      );
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    async aboutDialog => {
+      // Once the state is pending but langpacks aren't complete the about
+      // dialog should still be showing downloading.
+      TestUtils.waitForCondition(() => {
+        return readStatusFile() == STATE_PENDING;
+      });
+
+      is(
+        aboutDialog.gAppUpdater.selectedPanel.id,
+        "downloading",
+        "UI should still show as downloading."
+      );
+
+      let { appVersion, resolve } = await lankpackCall;
+      is(
+        appVersion,
+        Services.appinfo.version,
+        "Should see the right app version."
+      );
+      resolve();
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+
+  await SpecialPowers.popPrefEnv();
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloading_notify.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloading_notify.js
new file mode 100644
index 0000000000..cf067efe7d
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloading_notify.js
@@ -0,0 +1,67 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog background check for updates with the
+// "notify during download" feature turned on.
+add_task(async function aboutDialog_backgroundCheck_downloading_notify() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_NOTIFYDURINGDOWNLOAD, true]],
+  });
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&useSlowDownloadMar=1&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_DOWNLOADING,
+  };
+  await runAboutDialogUpdateTest(params, [
+    async function aboutDialog_downloading_notification() {
+      await TestUtils.waitForCondition(
+        () => PanelUI.menuButton.hasAttribute("badge-status"),
+        "Waiting for update badge",
+        undefined,
+        200
+      ).catch(e => {
+        // Instead of throwing let the check below fail the test.
+        logTestInfo(e);
+      });
+      is(
+        PanelUI.notificationPanel.state,
+        "closed",
+        "The window's doorhanger is closed."
+      );
+      ok(
+        PanelUI.menuButton.hasAttribute("badge-status"),
+        "The window has a badge."
+      );
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "update-downloading",
+        "The downloading badge is showing for the background window"
+      );
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+
+  await SpecialPowers.popPrefEnv();
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloading_staging.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloading_staging.js
new file mode 100644
index 0000000000..3f6b476e1b
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_downloading_staging.js
@@ -0,0 +1,68 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog background check for updates
+// with the About Dialog opened during downloading and stages the update.
+add_task(async function aboutDialog_backgroundCheck_downloading_staging() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  let lankpackCall = mockLangpackInstall();
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&useSlowDownloadMar=1&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_DOWNLOADING,
+  };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    async aboutDialog => {
+      // Once the state is applied but langpacks aren't complete the about
+      // dialog should still be showing applying.
+      TestUtils.waitForCondition(() => {
+        return readStatusFile() == STATE_APPLIED;
+      });
+
+      is(
+        aboutDialog.gAppUpdater.selectedPanel.id,
+        "applying",
+        "UI should still show as applying."
+      );
+
+      let { appVersion, resolve } = await lankpackCall;
+      is(
+        appVersion,
+        Services.appinfo.version,
+        "Should see the right app version."
+      );
+      resolve();
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_multiUpdate.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_multiUpdate.js
new file mode 100644
index 0000000000..b6c893ea15
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_bc_multiUpdate.js
@@ -0,0 +1,52 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const FIRST_UPDATE_VERSION = "999998.0";
+const SECOND_UPDATE_VERSION = "999999.0";
+
+function prepareToDownloadVersion(version) {
+  setUpdateURL(
+    URL_HTTP_UPDATE_SJS +
+      `?detailsURL=${gDetailsURL}&promptWaitTime=0&appVersion=${version}`
+  );
+}
+
+add_task(async function aboutDialog_backgroundCheck_multiUpdate() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let params = {
+    version: FIRST_UPDATE_VERSION,
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_PENDING,
+  };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+    () => {
+      prepareToDownloadVersion(SECOND_UPDATE_VERSION);
+      gAUS.checkForBackgroundUpdates();
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_apply_blocked.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_apply_blocked.js
new file mode 100644
index 0000000000..6cb2b9d10d
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_apply_blocked.js
@@ -0,0 +1,94 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { PromptTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/PromptTestUtils.sys.mjs"
+);
+
+const BUILDER_URL = "https://example.com/document-builder.sjs?html=";
+const PAGE_MARKUP = `
+<html>
+<head>
+  <script>
+    window.onbeforeunload = function() {
+      return true;
+    };
+  </script>
+</head>
+<body>TEST PAGE</body>
+</html>
+`;
+const TEST_URL = BUILDER_URL + encodeURI(PAGE_MARKUP);
+
+add_setup(async () => {
+  await SpecialPowers.pushPrefEnv({
+    set: [["dom.require_user_interaction_for_beforeunload", false]],
+  });
+});
+
+// Test for About Dialog foreground check for updates
+// and apply but restart is blocked by a page.
+add_task(async function aboutDialog_foregroundCheck_apply_blocked() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_URL);
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  let aboutDialog;
+  let handlePromise = (async () => {
+    let dialog = await PromptTestUtils.waitForPrompt(window, {
+      modalType: Ci.nsIPrompt.MODAL_TYPE_CONTENT,
+      promptType: "confirmEx",
+    });
+    Assert.equal(
+      aboutDialog.gAppUpdater.selectedPanel.id,
+      "restarting",
+      "The restarting panel should be displayed"
+    );
+
+    await PromptTestUtils.handlePrompt(dialog, { buttonNumClick: 1 });
+  })();
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1&promptWaitTime=0" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    async function getAboutDialogHandle(dialog) {
+      aboutDialog = dialog;
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+      forceApply: true,
+    },
+    async function ensureDialogHasBeenCanceled() {
+      await handlePromise;
+    },
+    // A final check to ensure that we are back in the apply state.
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+
+  BrowserTestUtils.removeTab(tab, { skipPermitUnload: true });
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_cantApply.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_cantApply.js
new file mode 100644
index 0000000000..cd659ef74b
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_cantApply.js
@@ -0,0 +1,24 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// without the ability to apply updates.
+add_task(async function aboutDialog_foregroundCheck_cantApply() {
+  lockWriteTestFile();
+
+  let params = {};
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "manualUpdate",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_malformedXML.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_malformedXML.js
new file mode 100644
index 0000000000..529a4c7a63
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_malformedXML.js
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with a malformed update XML file.
+add_task(async function aboutDialog_foregroundCheck_malformedXML() {
+  let params = { queryString: "&xmlMalformed=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "checkingFailed",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_noUpdate.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_noUpdate.js
new file mode 100644
index 0000000000..2bd23cddf0
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_noUpdate.js
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with no update available.
+add_task(async function aboutDialog_foregroundCheck_noUpdate() {
+  let params = { queryString: "&noUpdates=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "noUpdatesFound",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_otherInstance.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_otherInstance.js
new file mode 100644
index 0000000000..fa1110effd
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_otherInstance.js
@@ -0,0 +1,19 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with another application instance handling updates.
+add_task(async function aboutDialog_foregroundCheck_otherInstance() {
+  setOtherInstanceHandlingUpdates();
+
+  let params = {};
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "otherInstanceHandlingUpdates",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_unsupported.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_unsupported.js
new file mode 100644
index 0000000000..22e3425967
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_check_unsupported.js
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with an unsupported update.
+add_task(async function aboutDialog_foregroundCheck_unsupported() {
+  let params = { queryString: "&unsupported=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "unsupportedSystem",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadAuto.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadAuto.js
new file mode 100644
index 0000000000..a80c9deac8
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadAuto.js
@@ -0,0 +1,62 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with an automatic download.
+add_task(async function aboutDialog_foregroundCheck_downloadAuto() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1&promptWaitTime=0" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    async function aboutDialog_restart_notification() {
+      await TestUtils.waitForCondition(
+        () => PanelUI.menuButton.hasAttribute("badge-status"),
+        "Waiting for update badge",
+        undefined,
+        200
+      ).catch(e => {
+        // Instead of throwing let the check below fail the test.
+        logTestInfo(e);
+      });
+      is(
+        PanelUI.notificationPanel.state,
+        "closed",
+        "The window's doorhanger is closed."
+      );
+      ok(
+        PanelUI.menuButton.hasAttribute("badge-status"),
+        "The window has a badge."
+      );
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "update-restart",
+        "The restart badge is showing for the background window"
+      );
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadAuto_staging.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadAuto_staging.js
new file mode 100644
index 0000000000..e212b0c611
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadAuto_staging.js
@@ -0,0 +1,46 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with an automatic download and update staging.
+add_task(async function aboutDialog_foregroundCheck_downloadAuto_staging() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadOptIn.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadOptIn.js
new file mode 100644
index 0000000000..5a2ff513ad
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadOptIn.js
@@ -0,0 +1,44 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with a manual download.
+add_task(async function aboutDialog_foregroundCheck_downloadOptIn() {
+  await UpdateUtils.setAppUpdateAutoEnabled(false);
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloadAndInstall",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadOptIn_staging.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadOptIn_staging.js
new file mode 100644
index 0000000000..3ed331ec64
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_downloadOptIn_staging.js
@@ -0,0 +1,52 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with a manual download and update staging.
+add_task(async function aboutDialog_foregroundCheck_downloadOptIn_staging() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+  await UpdateUtils.setAppUpdateAutoEnabled(false);
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloadAndInstall",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_network_failure.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_network_failure.js
new file mode 100644
index 0000000000..8e25b96d7f
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_network_failure.js
@@ -0,0 +1,18 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates which fails, because it is
+// impossible to connect to the update server
+add_task(async function aboutDialog_foregroundCheck_network_failure() {
+  let params = {
+    baseURL: "https://localhost:7777",
+  };
+
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingFailed",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_network_offline.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_network_offline.js
new file mode 100644
index 0000000000..9f81573e23
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_network_offline.js
@@ -0,0 +1,31 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates which fails, because the
+// browser is in offline mode and `localhost` cannot be resolved.
+add_task(async function aboutDialog_foregroundCheck_network_offline() {
+  info("[OFFLINE] setting Services.io.offline (do not forget to reset it!)");
+  // avoid that real network connectivity changes influence the test execution
+  Services.io.manageOfflineStatus = false;
+  Services.io.offline = true;
+  registerCleanupFunction(() => {
+    info("[ONLINE] Resetting Services.io.offline");
+    Services.io.offline = false;
+    Services.io.manageOfflineStatus = true;
+  });
+
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["network.disable-localhost-when-offline", true],
+      ["network.dns.offline-localhost", false],
+    ],
+  });
+
+  await runAboutDialogUpdateTest({}, [
+    {
+      panelId: "checkingFailed",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_completeBadSize.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_completeBadSize.js
new file mode 100644
index 0000000000..fdc7d3407e
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_completeBadSize.js
@@ -0,0 +1,36 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with a complete bad size patch.
+add_task(async function aboutDialog_foregroundCheck_completeBadSize() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "complete", bitsResult: gBadSizeResult };
+    downloadInfo[1] = { patchType: "complete", internalResult: gBadSizeResult };
+  } else {
+    downloadInfo[0] = { patchType: "complete", internalResult: gBadSizeResult };
+  }
+
+  let params = { queryString: "&completePatchOnly=1&invalidCompleteSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "downloadFailed",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_partialBadSize.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_partialBadSize.js
new file mode 100644
index 0000000000..411fb25969
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_partialBadSize.js
@@ -0,0 +1,36 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with a partial bad size patch.
+add_task(async function aboutDialog_foregroundCheck_partialBadSize() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: gBadSizeResult };
+    downloadInfo[1] = { patchType: "partial", internalResult: gBadSizeResult };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: gBadSizeResult };
+  }
+
+  let params = { queryString: "&partialPatchOnly=1&invalidPartialSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "downloadFailed",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_partialBadSize_complete.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_partialBadSize_complete.js
new file mode 100644
index 0000000000..396be1e930
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_partialBadSize_complete.js
@@ -0,0 +1,38 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with a partial bad size patch and a complete patch.
+add_task(async function aboutDialog_foregroundCheck_partialBadSize_complete() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: gBadSizeResult };
+    downloadInfo[1] = { patchType: "partial", internalResult: gBadSizeResult };
+    downloadInfo[2] = { patchType: "complete", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: gBadSizeResult };
+    downloadInfo[1] = { patchType: "complete", internalResult: "0" };
+  }
+
+  let params = { queryString: "&invalidPartialSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_partialBadSize_completeBadSize.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_partialBadSize_completeBadSize.js
new file mode 100644
index 0000000000..fb10250a49
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_fc_patch_partialBadSize_completeBadSize.js
@@ -0,0 +1,53 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for About Dialog foreground check for updates
+// with a partial bad size patch and a complete bad size patch.
+add_task(
+  async function aboutDialog_foregroundCheck_partialBadSize_completeBadSize() {
+    let downloadInfo = [];
+    if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+      downloadInfo[0] = { patchType: "partial", bitsResult: gBadSizeResult };
+      downloadInfo[1] = {
+        patchType: "partial",
+        internalResult: gBadSizeResult,
+      };
+      downloadInfo[2] = { patchType: "complete", bitsResult: gBadSizeResult };
+      downloadInfo[3] = {
+        patchType: "complete",
+        internalResult: gBadSizeResult,
+      };
+    } else {
+      downloadInfo[0] = {
+        patchType: "partial",
+        internalResult: gBadSizeResult,
+      };
+      downloadInfo[1] = {
+        patchType: "complete",
+        internalResult: gBadSizeResult,
+      };
+    }
+
+    let params = { queryString: "&invalidPartialSize=1&invalidCompleteSize=1" };
+    await runAboutDialogUpdateTest(params, [
+      {
+        panelId: "checkingForUpdates",
+        checkActiveUpdate: null,
+        continueFile: CONTINUE_CHECK,
+      },
+      {
+        panelId: "downloading",
+        checkActiveUpdate: { state: STATE_DOWNLOADING },
+        continueFile: CONTINUE_DOWNLOAD,
+        downloadInfo,
+      },
+      {
+        panelId: "downloadFailed",
+        checkActiveUpdate: null,
+        continueFile: null,
+      },
+    ]);
+  }
+);
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutDialog_internalError.js b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_internalError.js
new file mode 100644
index 0000000000..d8d20ea05a
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutDialog_internalError.js
@@ -0,0 +1,35 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+ChromeUtils.defineESModuleGetters(this, {
+  AppUpdater: "resource://gre/modules/AppUpdater.sys.mjs",
+  sinon: "resource://testing-common/Sinon.sys.mjs",
+});
+
+add_setup(function setup_internalErrorTest() {
+  const sandbox = sinon.createSandbox();
+  sandbox.stub(AppUpdater.prototype, "aus").get(() => {
+    throw new Error("intentional test error");
+  });
+  sandbox.stub(AppUpdater.prototype, "checker").get(() => {
+    throw new Error("intentional test error");
+  });
+  sandbox.stub(AppUpdater.prototype, "um").get(() => {
+    throw new Error("intentional test error");
+  });
+  registerCleanupFunction(() => {
+    sandbox.restore();
+  });
+});
+
+// Test for the About dialog's internal error handling.
+add_task(async function aboutDialog_internalError() {
+  let params = {};
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "internalError",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_backgroundUpdateSetting.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_backgroundUpdateSetting.js
new file mode 100644
index 0000000000..88afa8fdbe
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_backgroundUpdateSetting.js
@@ -0,0 +1,172 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+"use strict";
+
+/**
+ * This file tests the background update UI in about:preferences.
+ */
+
+ChromeUtils.defineESModuleGetters(this, {
+  UpdateUtils: "resource://gre/modules/UpdateUtils.sys.mjs",
+});
+
+const BACKGROUND_UPDATE_PREF = "app.update.background.enabled";
+
+add_task(async function testBackgroundUpdateSettingUI() {
+  if (!AppConstants.MOZ_UPDATE_AGENT) {
+    // The element that we are testing in about:preferences is #ifdef'ed out of
+    // the file if MOZ_UPDATE_AGENT isn't defined. So there is nothing to
+    // test in that case.
+    logTestInfo(
+      `
+===============================================================================
+WARNING! This test involves background update, but background tasks are
+         disabled. This test will unconditionally pass since the feature it
+         wants to test isn't available.
+===============================================================================
+`
+    );
+    // Some of our testing environments do not consider a test to have passed if
+    // it didn't make any assertions.
+    ok(true, "Unconditionally passing test");
+    return;
+  }
+
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    "about:preferences"
+  );
+
+  const originalBackgroundUpdateVal = await UpdateUtils.readUpdateConfigSetting(
+    BACKGROUND_UPDATE_PREF
+  );
+  const originalUpdateAutoVal = await UpdateUtils.getAppUpdateAutoEnabled();
+  registerCleanupFunction(async () => {
+    await BrowserTestUtils.removeTab(tab);
+    await UpdateUtils.writeUpdateConfigSetting(
+      BACKGROUND_UPDATE_PREF,
+      originalBackgroundUpdateVal
+    );
+    await UpdateUtils.setAppUpdateAutoEnabled(originalUpdateAutoVal);
+  });
+
+  // If auto update is disabled, the control for background update should be
+  // disabled, since we cannot update in the background if we can't update
+  // automatically.
+  await UpdateUtils.setAppUpdateAutoEnabled(false);
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [UpdateUtils.PER_INSTALLATION_PREFS_SUPPORTED],
+    async perInstallationPrefsSupported => {
+      let backgroundUpdateCheckbox =
+        content.document.getElementById("backgroundUpdate");
+      is(
+        backgroundUpdateCheckbox.hidden,
+        !perInstallationPrefsSupported,
+        `The background update UI should ${
+          perInstallationPrefsSupported ? "not" : ""
+        } be hidden when and perInstallationPrefsSupported is ` +
+          `${perInstallationPrefsSupported}`
+      );
+      if (perInstallationPrefsSupported) {
+        is(
+          backgroundUpdateCheckbox.disabled,
+          true,
+          `The background update UI should be disabled when auto update is ` +
+            `disabled`
+        );
+      }
+    }
+  );
+
+  if (!UpdateUtils.PER_INSTALLATION_PREFS_SUPPORTED) {
+    // The remaining tests only make sense on platforms where per-installation
+    // prefs are supported and the UI will ever actually be displayed
+    return;
+  }
+
+  await UpdateUtils.setAppUpdateAutoEnabled(true);
+  await UpdateUtils.writeUpdateConfigSetting(BACKGROUND_UPDATE_PREF, true);
+
+  await SpecialPowers.spawn(tab.linkedBrowser, [], async function () {
+    let backgroundUpdateCheckbox =
+      content.document.getElementById("backgroundUpdate");
+    is(
+      backgroundUpdateCheckbox.disabled,
+      false,
+      `The background update UI should not be disabled when auto update is ` +
+        `enabled`
+    );
+
+    is(
+      backgroundUpdateCheckbox.checked,
+      true,
+      "After enabling background update, the checkbox should be checked"
+    );
+
+    // Note that this action results in asynchronous activity. Normally when
+    // we change the update config, we await on the function to wait for the
+    // value to be written to the disk. We can't easily await on the UI state
+    // though. Luckily, we don't have to because reads/writes of the config file
+    // are serialized. So when we verify the written value by awaiting on
+    // readUpdateConfigSetting(), that will also wait for the value to be
+    // written to disk and for this UI to react to that.
+    backgroundUpdateCheckbox.click();
+  });
+
+  is(
+    await UpdateUtils.readUpdateConfigSetting(BACKGROUND_UPDATE_PREF),
+    false,
+    "Toggling the checkbox should have changed the setting value to false"
+  );
+
+  await SpecialPowers.spawn(tab.linkedBrowser, [], async function () {
+    let backgroundUpdateCheckbox =
+      content.document.getElementById("backgroundUpdate");
+    is(
+      backgroundUpdateCheckbox.checked,
+      false,
+      "After toggling the checked checkbox, it should be unchecked."
+    );
+
+    // Like the last call like this one, this initiates asynchronous behavior.
+    backgroundUpdateCheckbox.click();
+  });
+
+  is(
+    await UpdateUtils.readUpdateConfigSetting(BACKGROUND_UPDATE_PREF),
+    true,
+    "Toggling the checkbox should have changed the setting value to true"
+  );
+
+  await SpecialPowers.spawn(tab.linkedBrowser, [], async function () {
+    is(
+      content.document.getElementById("backgroundUpdate").checked,
+      true,
+      "After toggling the unchecked checkbox, it should be checked"
+    );
+  });
+
+  // Test that the UI reacts to observed setting changes properly.
+  await UpdateUtils.writeUpdateConfigSetting(BACKGROUND_UPDATE_PREF, false);
+
+  await SpecialPowers.spawn(tab.linkedBrowser, [], async function () {
+    is(
+      content.document.getElementById("backgroundUpdate").checked,
+      false,
+      "Externally disabling background update should uncheck the checkbox"
+    );
+  });
+
+  await UpdateUtils.writeUpdateConfigSetting(BACKGROUND_UPDATE_PREF, true);
+
+  await SpecialPowers.spawn(tab.linkedBrowser, [], async function () {
+    is(
+      content.document.getElementById("backgroundUpdate").checked,
+      true,
+      "Externally enabling background update should check the checkbox"
+    );
+  });
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded.js
new file mode 100644
index 0000000000..6df4ee7ff5
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded.js
@@ -0,0 +1,17 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences background check for updates
+// with the update downloaded when about:preferences is opened.
+add_task(async function aboutPrefs_backgroundCheck_downloaded() {
+  let params = { backgroundUpdate: true, waitForUpdateState: STATE_PENDING };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded_staged.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded_staged.js
new file mode 100644
index 0000000000..749a8f0b07
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded_staged.js
@@ -0,0 +1,28 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences background check for updates
+// with the update downloaded and staged when about:preferences is opened.
+add_task(async function aboutPrefs_backgroundCheck_downloaded_staged() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    continueFile: CONTINUE_STAGING,
+    waitForUpdateState: STATE_APPLIED,
+  };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded_staging.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded_staging.js
new file mode 100644
index 0000000000..73804cdf7a
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded_staging.js
@@ -0,0 +1,59 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences background check for updates
+// with the update downloaded and about:preferences opened during staging.
+add_task(async function aboutPrefs_backgroundCheck_downloaded_staged() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let lankpackCall = mockLangpackInstall();
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_PENDING,
+  };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    async tab => {
+      // Once the state is pending but langpacks aren't complete the about
+      // dialog should still be showing downloading.
+      TestUtils.waitForCondition(() => {
+        return readStatusFile() == STATE_APPLIED;
+      });
+
+      let updateDeckId = await SpecialPowers.spawn(
+        tab.linkedBrowser,
+        [],
+        () => {
+          return content.gAppUpdater.selectedPanel.id;
+        }
+      );
+
+      is(updateDeckId, "applying", "UI should still show as applying.");
+
+      let { appVersion, resolve } = await lankpackCall;
+      is(
+        appVersion,
+        Services.appinfo.version,
+        "Should see the right app version."
+      );
+      resolve();
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded_stagingFailure.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded_stagingFailure.js
new file mode 100644
index 0000000000..9755fe167b
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloaded_stagingFailure.js
@@ -0,0 +1,29 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences background check for updates
+// with the update downloaded and staging has failed when the about:preferences
+// is opened.
+add_task(async function aboutPrefs_backgroundCheck_downloaded_stagingFailure() {
+  Services.env.set("MOZ_TEST_STAGING_ERROR", "1");
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&completePatchOnly=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_PENDING,
+  };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloading.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloading.js
new file mode 100644
index 0000000000..d9034296b0
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloading.js
@@ -0,0 +1,63 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences background check for updates
+// with about:preferences opened during downloading.
+add_task(async function aboutPrefs_backgroundCheck_downloading() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  let lankpackCall = mockLangpackInstall();
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&useSlowDownloadMar=1&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_DOWNLOADING,
+  };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    async tab => {
+      // Once the state is pending but langpacks aren't complete the about
+      // dialog should still be showing downloading.
+      TestUtils.waitForCondition(() => {
+        return readStatusFile() == STATE_PENDING;
+      });
+
+      let updateDeckId = await SpecialPowers.spawn(
+        tab.linkedBrowser,
+        [],
+        () => {
+          return content.gAppUpdater.selectedPanel.id;
+        }
+      );
+
+      is(updateDeckId, "downloading", "UI should still show as downloading.");
+
+      let { appVersion, resolve } = await lankpackCall;
+      is(
+        appVersion,
+        Services.appinfo.version,
+        "Should see the right app version."
+      );
+      resolve();
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloading_staging.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloading_staging.js
new file mode 100644
index 0000000000..8085ec4c2c
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_downloading_staging.js
@@ -0,0 +1,72 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences background check for updates
+// with about:preferences opened during downloading and stages the update.
+add_task(async function aboutPrefs_backgroundCheck_downloading_staging() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  let lankpackCall = mockLangpackInstall();
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&useSlowDownloadMar=1&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_DOWNLOADING,
+  };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    async tab => {
+      // Once the state is pending but langpacks aren't complete the about
+      // dialog should still be showing downloading.
+      TestUtils.waitForCondition(() => {
+        return readStatusFile() == STATE_APPLIED;
+      });
+
+      let updateDeckId = await SpecialPowers.spawn(
+        tab.linkedBrowser,
+        [],
+        () => {
+          return content.gAppUpdater.selectedPanel.id;
+        }
+      );
+
+      is(updateDeckId, "applying", "UI should still show as applying.");
+
+      let { appVersion, resolve } = await lankpackCall;
+      is(
+        appVersion,
+        Services.appinfo.version,
+        "Should see the right app version."
+      );
+      resolve();
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_multiUpdate.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_multiUpdate.js
new file mode 100644
index 0000000000..9ccf593db5
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_bc_multiUpdate.js
@@ -0,0 +1,52 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const FIRST_UPDATE_VERSION = "999998.0";
+const SECOND_UPDATE_VERSION = "999999.0";
+
+function prepareToDownloadVersion(version) {
+  setUpdateURL(
+    URL_HTTP_UPDATE_SJS +
+      `?detailsURL=${gDetailsURL}&promptWaitTime=0&appVersion=${version}`
+  );
+}
+
+add_task(async function aboutPrefs_backgroundCheck_multiUpdate() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let params = {
+    version: FIRST_UPDATE_VERSION,
+    backgroundUpdate: true,
+    waitForUpdateState: STATE_PENDING,
+  };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+    () => {
+      prepareToDownloadVersion(SECOND_UPDATE_VERSION);
+      gAUS.checkForBackgroundUpdates();
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_apply_blocked.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_apply_blocked.js
new file mode 100644
index 0000000000..22daa5e256
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_apply_blocked.js
@@ -0,0 +1,96 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { PromptTestUtils } = ChromeUtils.importESModule(
+  "resource://testing-common/PromptTestUtils.sys.mjs"
+);
+
+const BUILDER_URL = "https://example.com/document-builder.sjs?html=";
+const PAGE_MARKUP = `
+<html>
+<head>
+  <script>
+    window.onbeforeunload = function() {
+      return true;
+    };
+  </script>
+</head>
+<body>TEST PAGE</body>
+</html>
+`;
+const TEST_URL = BUILDER_URL + encodeURI(PAGE_MARKUP);
+
+add_setup(async () => {
+  await SpecialPowers.pushPrefEnv({
+    set: [["dom.require_user_interaction_for_beforeunload", false]],
+  });
+});
+
+// Test for About Dialog foreground check for updates
+// and apply but restart is blocked by a page.
+add_task(async function aboutDialog_foregroundCheck_apply_blocked() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, TEST_URL);
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  let prefsTab;
+  let handlePromise = (async () => {
+    let dialog = await PromptTestUtils.waitForPrompt(window, {
+      modalType: Ci.nsIPrompt.MODAL_TYPE_CONTENT,
+      promptType: "confirmEx",
+    });
+    await SpecialPowers.spawn(prefsTab.linkedBrowser, [], async () => {
+      Assert.equal(
+        content.gAppUpdater.selectedPanel.id,
+        "restarting",
+        "The restarting panel should be displayed"
+      );
+    });
+
+    await PromptTestUtils.handlePrompt(dialog, { buttonNumClick: 1 });
+  })();
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1&promptWaitTime=0" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    async function getPrefsTab(tab) {
+      prefsTab = tab;
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+      forceApply: true,
+    },
+    async function ensureDialogHasBeenCanceled() {
+      await handlePromise;
+    },
+    // A final check to ensure that we are back in the apply state.
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+
+  BrowserTestUtils.removeTab(tab, { skipPermitUnload: true });
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_cantApply.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_cantApply.js
new file mode 100644
index 0000000000..aac9b33134
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_cantApply.js
@@ -0,0 +1,24 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// without the ability to apply updates.
+add_task(async function aboutPrefs_foregroundCheck_cantApply() {
+  lockWriteTestFile();
+
+  let params = {};
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "manualUpdate",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_malformedXML.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_malformedXML.js
new file mode 100644
index 0000000000..6d99a58e86
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_malformedXML.js
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with a malformed update XML file.
+add_task(async function aboutPrefs_foregroundCheck_malformedXML() {
+  let params = { queryString: "&xmlMalformed=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "checkingFailed",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_noUpdate.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_noUpdate.js
new file mode 100644
index 0000000000..a8f6c072f7
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_noUpdate.js
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with no update available.
+add_task(async function aboutPrefs_foregroundCheck_noUpdate() {
+  let params = { queryString: "&noUpdates=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "noUpdatesFound",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_otherInstance.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_otherInstance.js
new file mode 100644
index 0000000000..271c8f2837
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_otherInstance.js
@@ -0,0 +1,19 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with another application instance handling updates.
+add_task(async function aboutPrefs_foregroundCheck_otherInstance() {
+  setOtherInstanceHandlingUpdates();
+
+  let params = {};
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "otherInstanceHandlingUpdates",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_unsupported.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_unsupported.js
new file mode 100644
index 0000000000..e18ce31bc4
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_check_unsupported.js
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with an unsupported update.
+add_task(async function aboutPrefs_foregroundCheck_unsupported() {
+  let params = { queryString: "&unsupported=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "unsupportedSystem",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadAuto.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadAuto.js
new file mode 100644
index 0000000000..bd5fd18289
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadAuto.js
@@ -0,0 +1,37 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with an automatic download.
+add_task(async function aboutPrefs_foregroundCheck_downloadAuto() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadAuto_staging.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadAuto_staging.js
new file mode 100644
index 0000000000..1d9d082edd
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadAuto_staging.js
@@ -0,0 +1,46 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with an automatic download and update staging.
+add_task(async function aboutPrefs_foregroundCheck_downloadAuto_staging() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadOptIn.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadOptIn.js
new file mode 100644
index 0000000000..115e875b74
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadOptIn.js
@@ -0,0 +1,44 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with a manual download.
+add_task(async function aboutPrefs_foregroundCheck_downloadOptIn() {
+  await UpdateUtils.setAppUpdateAutoEnabled(false);
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloadAndInstall",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadOptIn_staging.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadOptIn_staging.js
new file mode 100644
index 0000000000..cff5d74701
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_downloadOptIn_staging.js
@@ -0,0 +1,52 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with a manual download and update staging.
+add_task(async function aboutPrefs_foregroundCheck_downloadOptIn_staging() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+  await UpdateUtils.setAppUpdateAutoEnabled(false);
+
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: "0" };
+  }
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloadAndInstall",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "applying",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: CONTINUE_STAGING,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_APPLIED },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_network_failure.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_network_failure.js
new file mode 100644
index 0000000000..fbf91c0e54
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_network_failure.js
@@ -0,0 +1,17 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates which fails,
+// because it is impossible to connect to the update server.
+add_task(async function aboutPrefs_foregroundCheck_network_failure() {
+  let params = {
+    baseURL: "https://localhost:7777",
+  };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingFailed",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_network_offline.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_network_offline.js
new file mode 100644
index 0000000000..7b5b6899b3
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_network_offline.js
@@ -0,0 +1,31 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates which fails because
+// the browser is in offline mode and `localhost` cannot be resolved.
+add_task(async function aboutPrefs_foregroundCheck_network_offline() {
+  info("[OFFLINE] Setting Services.io.offline (do not forget to reset it!)");
+  // avoid that real network connectivity changes influence the test execution
+  Services.io.manageOfflineStatus = false;
+  Services.io.offline = true;
+  registerCleanupFunction(() => {
+    info("[ONLINE] Resetting Services.io.offline");
+    Services.io.offline = false;
+    Services.io.manageOfflineStatus = true;
+  });
+
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["network.disable-localhost-when-offline", true],
+      ["network.dns.offline-localhost", false],
+    ],
+  });
+
+  await runAboutPrefsUpdateTest({}, [
+    {
+      panelId: "checkingFailed",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_completeBadSize.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_completeBadSize.js
new file mode 100644
index 0000000000..a36d3d9807
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_completeBadSize.js
@@ -0,0 +1,36 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with a complete bad size patch.
+add_task(async function aboutPrefs_foregroundCheck_completeBadSize() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "complete", bitsResult: gBadSizeResult };
+    downloadInfo[1] = { patchType: "complete", internalResult: gBadSizeResult };
+  } else {
+    downloadInfo[0] = { patchType: "complete", internalResult: gBadSizeResult };
+  }
+
+  let params = { queryString: "&completePatchOnly=1&invalidCompleteSize=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "downloadFailed",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_partialBadSize.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_partialBadSize.js
new file mode 100644
index 0000000000..060acd405a
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_partialBadSize.js
@@ -0,0 +1,36 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with a partial bad size patch.
+add_task(async function aboutPrefs_foregroundCheck_partialBadSize() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: gBadSizeResult };
+    downloadInfo[1] = { patchType: "partial", internalResult: gBadSizeResult };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: gBadSizeResult };
+  }
+
+  let params = { queryString: "&partialPatchOnly=1&invalidPartialSize=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "downloadFailed",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_partialBadSize_complete.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_partialBadSize_complete.js
new file mode 100644
index 0000000000..c6e5b5b20b
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_partialBadSize_complete.js
@@ -0,0 +1,38 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with a partial bad size patch and a complete patch.
+add_task(async function aboutPrefs_foregroundCheck_partialBadSize_complete() {
+  let downloadInfo = [];
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+    downloadInfo[0] = { patchType: "partial", bitsResult: gBadSizeResult };
+    downloadInfo[1] = { patchType: "partial", internalResult: gBadSizeResult };
+    downloadInfo[2] = { patchType: "complete", bitsResult: "0" };
+  } else {
+    downloadInfo[0] = { patchType: "partial", internalResult: gBadSizeResult };
+    downloadInfo[1] = { patchType: "complete", internalResult: "0" };
+  }
+
+  let params = { queryString: "&invalidPartialSize=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_partialBadSize_completeBadSize.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_partialBadSize_completeBadSize.js
new file mode 100644
index 0000000000..62abdc3af5
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_fc_patch_partialBadSize_completeBadSize.js
@@ -0,0 +1,53 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for about:preferences foreground check for updates
+// with a partial bad size patch and a complete bad size patch.
+add_task(
+  async function aboutPrefs_foregroundCheck_partialBadSize_completeBadSize() {
+    let downloadInfo = [];
+    if (Services.prefs.getBoolPref(PREF_APP_UPDATE_BITS_ENABLED)) {
+      downloadInfo[0] = { patchType: "partial", bitsResult: gBadSizeResult };
+      downloadInfo[1] = {
+        patchType: "partial",
+        internalResult: gBadSizeResult,
+      };
+      downloadInfo[2] = { patchType: "complete", bitsResult: gBadSizeResult };
+      downloadInfo[3] = {
+        patchType: "complete",
+        internalResult: gBadSizeResult,
+      };
+    } else {
+      downloadInfo[0] = {
+        patchType: "partial",
+        internalResult: gBadSizeResult,
+      };
+      downloadInfo[1] = {
+        patchType: "complete",
+        internalResult: gBadSizeResult,
+      };
+    }
+
+    let params = { queryString: "&invalidPartialSize=1&invalidCompleteSize=1" };
+    await runAboutPrefsUpdateTest(params, [
+      {
+        panelId: "checkingForUpdates",
+        checkActiveUpdate: null,
+        continueFile: CONTINUE_CHECK,
+      },
+      {
+        panelId: "downloading",
+        checkActiveUpdate: { state: STATE_DOWNLOADING },
+        continueFile: CONTINUE_DOWNLOAD,
+        downloadInfo,
+      },
+      {
+        panelId: "downloadFailed",
+        checkActiveUpdate: null,
+        continueFile: null,
+      },
+    ]);
+  }
+);
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_internalError.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_internalError.js
new file mode 100644
index 0000000000..95a7ec1063
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_internalError.js
@@ -0,0 +1,35 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+ChromeUtils.defineESModuleGetters(this, {
+  AppUpdater: "resource://gre/modules/AppUpdater.sys.mjs",
+  sinon: "resource://testing-common/Sinon.sys.mjs",
+});
+
+add_setup(function setup_internalErrorTest() {
+  const sandbox = sinon.createSandbox();
+  sandbox.stub(AppUpdater.prototype, "aus").get(() => {
+    throw new Error("intentional test error");
+  });
+  sandbox.stub(AppUpdater.prototype, "checker").get(() => {
+    throw new Error("intentional test error");
+  });
+  sandbox.stub(AppUpdater.prototype, "um").get(() => {
+    throw new Error("intentional test error");
+  });
+  registerCleanupFunction(() => {
+    sandbox.restore();
+  });
+});
+
+// Test for about:preferences internal error handling.
+add_task(async function aboutPrefs_internalError() {
+  let params = {};
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "internalError",
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_settings.js b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_settings.js
new file mode 100644
index 0000000000..db1b538d14
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_aboutPrefs_settings.js
@@ -0,0 +1,151 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+// Changes, then verifies the value of app.update.auto via the about:preferences
+// UI. Requires a tab with about:preferences open to be passed in.
+async function changeAndVerifyPref(tab, newConfigValue) {
+  await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [{ newConfigValue }],
+    async function ({ newConfigValue }) {
+      let radioId = newConfigValue ? "autoDesktop" : "manualDesktop";
+      let radioElement = content.document.getElementById(radioId);
+      let updateRadioGroup = radioElement.radioGroup;
+      let promise = ContentTaskUtils.waitForEvent(
+        updateRadioGroup,
+        "ProcessedUpdatePrefChange"
+      );
+      radioElement.click();
+      await promise;
+
+      is(
+        updateRadioGroup.value,
+        `${newConfigValue}`,
+        "Update preference should match expected"
+      );
+      is(
+        updateRadioGroup.disabled,
+        false,
+        "Update preferences should no longer be disabled"
+      );
+    }
+  );
+
+  let configValueRead = await UpdateUtils.getAppUpdateAutoEnabled();
+  is(
+    configValueRead,
+    newConfigValue,
+    "Value returned should have matched the expected value"
+  );
+}
+
+async function changeAndVerifyUpdateWrites({
+  tab,
+  newConfigValue,
+  discardUpdate,
+  expectPrompt,
+  expectRemainingUpdate,
+}) {
+  // A value of 1 will keep the update and a value of 0 will discard the update
+  // when the prompt service is called when the value of app.update.auto is
+  // changed to false.
+  let confirmExReply = discardUpdate ? 0 : 1;
+  let didPrompt = false;
+  let promptService = {
+    QueryInterface: ChromeUtils.generateQI(["nsIPromptService"]),
+    confirmEx(...args) {
+      promptService._confirmExArgs = args;
+      didPrompt = true;
+      return confirmExReply;
+    },
+  };
+  Services.prompt = promptService;
+  await changeAndVerifyPref(tab, newConfigValue);
+  is(
+    didPrompt,
+    expectPrompt,
+    `We should ${expectPrompt ? "" : "not "}be prompted`
+  );
+  is(
+    !!gUpdateManager.readyUpdate,
+    expectRemainingUpdate,
+    `There should ${expectRemainingUpdate ? "" : "not "}be a ready update`
+  );
+}
+
+add_task(async function testUpdateAutoPrefUI() {
+  let tab = await BrowserTestUtils.openNewForegroundTab(
+    gBrowser,
+    "about:preferences"
+  );
+
+  // Hack: make the test run faster:
+  await SpecialPowers.spawn(tab.linkedBrowser, [], () => {
+    content.gMainPane._minUpdatePrefDisableTime = 10;
+  });
+
+  info("Enable automatic updates and check that works.");
+  await changeAndVerifyPref(tab, true);
+  ok(
+    !gUpdateManager.downloadingUpdate,
+    "There should not be a downloading update"
+  );
+  ok(!gUpdateManager.readyUpdate, "There should not be a ready update");
+
+  info("Disable automatic updates and check that works.");
+  await changeAndVerifyPref(tab, false);
+  ok(
+    !gUpdateManager.downloadingUpdate,
+    "There should not be a downloading update"
+  );
+  ok(!gUpdateManager.readyUpdate, "There should not be a ready update");
+
+  let patchProps = { state: STATE_PENDING };
+  let patches = getLocalPatchString(patchProps);
+  let updateProps = { checkInterval: "1" };
+  let updates = getLocalUpdateString(updateProps, patches);
+  writeUpdatesToXMLFile(getLocalUpdatesXMLString(updates), true);
+  writeStatusFile(STATE_PENDING);
+  reloadUpdateManagerData();
+  ok(!!gUpdateManager.readyUpdate, "There should be a ready update");
+
+  let { prompt } = Services;
+  registerCleanupFunction(() => {
+    Services.prompt = prompt;
+  });
+
+  // Setting the value to false will call the prompt service and when we
+  // don't discard the update there should still be an active update afterwards.
+  await changeAndVerifyUpdateWrites({
+    tab,
+    newConfigValue: false,
+    discardUpdate: false,
+    expectPrompt: true,
+    expectRemainingUpdate: true,
+  });
+
+  // Setting the value to true should not call the prompt service so there
+  // should still be an active update, even if we indicate we can discard
+  // the update in a hypothetical prompt.
+  await changeAndVerifyUpdateWrites({
+    tab,
+    newConfigValue: true,
+    discardUpdate: true,
+    expectPrompt: false,
+    expectRemainingUpdate: true,
+  });
+
+  // Setting the value to false will call the prompt service, and we do
+  // discard the update, so there should not be an active update.
+  await changeAndVerifyUpdateWrites({
+    tab,
+    newConfigValue: false,
+    discardUpdate: true,
+    expectPrompt: true,
+    expectRemainingUpdate: false,
+  });
+
+  await BrowserTestUtils.removeTab(tab);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_check_cantApply.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_check_cantApply.js
new file mode 100644
index 0000000000..90f4c385cc
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_check_cantApply.js
@@ -0,0 +1,18 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_check_cantApply() {
+  lockWriteTestFile();
+
+  let params = { checkAttempts: 1, queryString: "&promptWaitTime=0" };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-manual",
+      button: "button",
+      checkActiveUpdate: null,
+      pageURLs: { whatsNew: gDetailsURL, manual: URL_MANUAL_UPDATE },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_check_malformedXML.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_check_malformedXML.js
new file mode 100644
index 0000000000..d83bc70b6f
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_check_malformedXML.js
@@ -0,0 +1,26 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_check_malformedXML() {
+  const maxBackgroundErrors = 10;
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_BACKGROUNDMAXERRORS, maxBackgroundErrors]],
+  });
+
+  let params = {
+    checkAttempts: maxBackgroundErrors,
+    queryString: "&xmlMalformed=1",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      // If the update check fails 10 consecutive attempts then the manual
+      // update doorhanger.
+      notificationId: "update-manual",
+      button: "button",
+      checkActiveUpdate: null,
+      pageURLs: { whatsNew: gDetailsURL, manual: URL_MANUAL_UPDATE },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_check_unsupported.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_check_unsupported.js
new file mode 100644
index 0000000000..02aaab1064
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_check_unsupported.js
@@ -0,0 +1,94 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Test for doorhanger background check for updates
+// with an unsupported update.
+add_task(async function doorhanger_bc_check_unsupported() {
+  let params = { checkAttempts: 1, queryString: "&unsupported=1" };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-unsupported",
+      button: "button",
+      pageURLs: { manual: gDetailsURL },
+    },
+    async function doorhanger_unsupported_persist() {
+      await TestUtils.waitForCondition(
+        () => PanelUI.menuButton.hasAttribute("badge-status"),
+        "Waiting for update badge",
+        undefined,
+        200
+      ).catch(e => {
+        // Instead of throwing let the check below fail the test.
+        logTestInfo(e);
+      });
+      is(
+        PanelUI.notificationPanel.state,
+        "closed",
+        "The window's doorhanger is closed."
+      );
+      ok(
+        PanelUI.menuButton.hasAttribute("badge-status"),
+        "The window has a badge."
+      );
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "update-unsupported",
+        "The correct badge is showing for the background window"
+      );
+
+      // Test persistence of the badge when the client has restarted by
+      // resetting the UpdateListener.
+      UpdateListener.reset();
+      is(
+        PanelUI.notificationPanel.state,
+        "closed",
+        "The window's doorhanger is closed."
+      );
+      ok(
+        !PanelUI.menuButton.hasAttribute("badge-status"),
+        "The window does not have a badge."
+      );
+      UpdateListener.maybeShowUnsupportedNotification();
+      is(
+        PanelUI.notificationPanel.state,
+        "closed",
+        "The window's doorhanger is closed."
+      );
+      ok(
+        PanelUI.menuButton.hasAttribute("badge-status"),
+        "The window has a badge."
+      );
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "update-unsupported",
+        "The correct badge is showing for the background window."
+      );
+    },
+  ]);
+
+  params = {
+    checkAttempts: 1,
+    queryString: "&invalidCompleteSize=1&promptWaitTime=0",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_PENDING },
+    },
+    async function doorhanger_unsupported_removed() {
+      // Test that finding an update removes the app.update.unsupported.url
+      // preference.
+      let unsupportedURL = Services.prefs.getCharPref(
+        PREF_APP_UPDATE_UNSUPPORTED_URL,
+        null
+      );
+      ok(
+        !unsupportedURL,
+        "The " + PREF_APP_UPDATE_UNSUPPORTED_URL + " preference was removed."
+      );
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadAutoFailures.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadAutoFailures.js
new file mode 100644
index 0000000000..3678a440d2
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadAutoFailures.js
@@ -0,0 +1,35 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_downloadAutoFailures() {
+  const maxBackgroundErrors = 5;
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_BACKGROUNDMAXERRORS, maxBackgroundErrors]],
+  });
+
+  let params = { checkAttempts: 1, queryString: "&badURL=1" };
+  await runDoorhangerUpdateTest(params, [
+    {
+      // If the update download fails maxBackgroundErrors download attempts then
+      // show the update available prompt.
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      // If the update process is unable to install the update show the manual
+      // update doorhanger.
+      notificationId: "update-manual",
+      button: "button",
+      checkActiveUpdate: null,
+      pageURLs: { manual: URL_MANUAL_UPDATE },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadAutoFailures_bgWin.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadAutoFailures_bgWin.js
new file mode 100644
index 0000000000..a4502d7626
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadAutoFailures_bgWin.js
@@ -0,0 +1,80 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_downloadAutoFailures_bgWin() {
+  function getBackgroundWindowHandler(destroyWindow) {
+    return async function () {
+      await TestUtils.waitForCondition(
+        () => PanelUI.menuButton.hasAttribute("badge-status"),
+        "Background window has a badge.",
+        undefined,
+        200
+      ).catch(e => {
+        // Instead of throwing let the check below fail the test.
+        logTestInfo(e);
+      });
+      ok(
+        PanelUI.menuButton.hasAttribute("badge-status"),
+        "PanelUI.menuButton should have a 'badge-status' attribute"
+      );
+      is(
+        PanelUI.notificationPanel.state,
+        "closed",
+        "The doorhanger is not showing for the background window"
+      );
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "update-available",
+        "The badge is showing for the background window"
+      );
+
+      let buttonEl = getNotificationButton(
+        extraWindow,
+        "update-available",
+        "button"
+      );
+      buttonEl.click();
+
+      if (destroyWindow) {
+        // The next popup may be shown during closeWindow or promiseFocus
+        // calls.
+        let waitForPopupShown = new Promise(resolve => {
+          window.addEventListener(
+            "popupshown",
+            () => {
+              executeSoon(resolve);
+            },
+            { once: true }
+          );
+        });
+        await BrowserTestUtils.closeWindow(extraWindow);
+        await SimpleTest.promiseFocus(window);
+        await waitForPopupShown;
+      }
+    };
+  }
+
+  const maxBackgroundErrors = 5;
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_BACKGROUNDMAXERRORS, maxBackgroundErrors]],
+  });
+
+  let extraWindow = await BrowserTestUtils.openNewBrowserWindow();
+  await SimpleTest.promiseFocus(extraWindow);
+
+  let params = { checkAttempts: 1, queryString: "&badURL=1", popupShown: true };
+  await runDoorhangerUpdateTest(params, [
+    getBackgroundWindowHandler(false),
+    getBackgroundWindowHandler(true),
+    {
+      // If the update process is unable to install the update show the manual
+      // update doorhanger.
+      notificationId: "update-manual",
+      button: "button",
+      checkActiveUpdate: null,
+      pageURLs: { manual: URL_MANUAL_UPDATE },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadOptIn.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadOptIn.js
new file mode 100644
index 0000000000..2237161863
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadOptIn.js
@@ -0,0 +1,25 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_downloadOptIn() {
+  await UpdateUtils.setAppUpdateAutoEnabled(false);
+
+  let params = {
+    checkAttempts: 1,
+    queryString: "&invalidCompleteSize=1&promptWaitTime=0",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_PENDING },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadOptIn_bgWin.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadOptIn_bgWin.js
new file mode 100644
index 0000000000..17dcce57ce
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadOptIn_bgWin.js
@@ -0,0 +1,63 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_downloadOptIn_bgWin() {
+  function getBackgroundWindowHandler() {
+    return async function () {
+      await TestUtils.waitForCondition(
+        () => PanelUI.menuButton.hasAttribute("badge-status"),
+        "Background window has a badge.",
+        undefined,
+        200
+      ).catch(e => {
+        // Instead of throwing let the check below fail the test.
+        logTestInfo(e);
+      });
+      ok(
+        PanelUI.menuButton.hasAttribute("badge-status"),
+        "PanelUI.menuButton should have a 'badge-status' attribute"
+      );
+      is(
+        PanelUI.notificationPanel.state,
+        "closed",
+        "The doorhanger is not showing for the background window"
+      );
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "update-available",
+        "The badge is showing for the background window"
+      );
+      let popupShownPromise = BrowserTestUtils.waitForEvent(
+        PanelUI.notificationPanel,
+        "popupshown"
+      );
+      await BrowserTestUtils.closeWindow(extraWindow);
+      await SimpleTest.promiseFocus(window);
+      await popupShownPromise;
+
+      let buttonEl = getNotificationButton(
+        window,
+        "update-available",
+        "button"
+      );
+      buttonEl.click();
+    };
+  }
+
+  await UpdateUtils.setAppUpdateAutoEnabled(false);
+
+  let extraWindow = await BrowserTestUtils.openNewBrowserWindow();
+  await SimpleTest.promiseFocus(extraWindow);
+
+  let params = { checkAttempts: 1, queryString: "&promptWaitTime=0" };
+  await runDoorhangerUpdateTest(params, [
+    getBackgroundWindowHandler(),
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_PENDING },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadOptIn_staging.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadOptIn_staging.js
new file mode 100644
index 0000000000..7ba2d67964
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloadOptIn_staging.js
@@ -0,0 +1,29 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_downloadOptIn_staging() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      // Tests the app.update.promptWaitTime pref
+      [PREF_APP_UPDATE_PROMPTWAITTIME, 0],
+      [PREF_APP_UPDATE_STAGING_ENABLED, true],
+    ],
+  });
+  await UpdateUtils.setAppUpdateAutoEnabled(false);
+
+  let params = { checkAttempts: 1, queryString: "&invalidCompleteSize=1" };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_APPLIED },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloaded.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloaded.js
new file mode 100644
index 0000000000..e29dad26fa
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloaded.js
@@ -0,0 +1,18 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_downloaded() {
+  let params = {
+    checkAttempts: 1,
+    queryString: "&invalidCompleteSize=1&promptWaitTime=0",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_PENDING },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloaded_disableBITS.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloaded_disableBITS.js
new file mode 100644
index 0000000000..5f89c95322
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloaded_disableBITS.js
@@ -0,0 +1,31 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_downloaded_disableBITS() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_BITS_ENABLED, true]],
+  });
+
+  let params = {
+    checkAttempts: 1,
+    queryString: "&promptWaitTime=0&disableBITS=true",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_PENDING },
+    },
+  ]);
+
+  let patch = getPatchOfType(
+    "partial",
+    gUpdateManager.readyUpdate
+  ).QueryInterface(Ci.nsIWritablePropertyBag);
+  ok(
+    !patch.getProperty("bitsId"),
+    "The selected patch should not have a bitsId property"
+  );
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloaded_staged.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloaded_staged.js
new file mode 100644
index 0000000000..50416608f2
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_downloaded_staged.js
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_downloaded_staged() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let params = {
+    checkAttempts: 1,
+    queryString: "&invalidCompleteSize=1&promptWaitTime=0",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_APPLIED },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_multiUpdate.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_multiUpdate.js
new file mode 100644
index 0000000000..07e7bf51fa
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_multiUpdate.js
@@ -0,0 +1,93 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * This test downloads 2 updates sequentially, and ensures that the doorhanger
+ * and badge do what they are supposed to do:
+ *   First thing after the first download, the doorhanger should be displayed.
+ *   Then download the next update.
+ *   While that update stages, the badge should be hidden to prevent restarting
+ *     to update while the update is staging.
+ *   Once the staging completes, the badge should return. The doorhanger should
+ *     not be shown at this time, because it has already been shown this
+ *     session.
+ */
+
+const FIRST_UPDATE_VERSION = "999998.0";
+const SECOND_UPDATE_VERSION = "999999.0";
+
+function prepareToDownloadVersion(version) {
+  setUpdateURL(
+    URL_HTTP_UPDATE_SJS +
+      `?detailsURL=${gDetailsURL}&promptWaitTime=0&appVersion=${version}`
+  );
+}
+
+add_task(async function doorhanger_bc_multiUpdate() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let params = {
+    checkAttempts: 1,
+    queryString: "&promptWaitTime=0",
+    version: FIRST_UPDATE_VERSION,
+    slowStaging: true,
+  };
+  await runDoorhangerUpdateTest(params, [
+    () => {
+      return continueFileHandler(CONTINUE_STAGING);
+    },
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_APPLIED },
+    },
+    async () => {
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "update-restart",
+        "Should have restart badge"
+      );
+
+      prepareToDownloadVersion(SECOND_UPDATE_VERSION);
+      let updateSwapped = waitForEvent("update-swap");
+      gAUS.checkForBackgroundUpdates();
+      await updateSwapped;
+      // The badge should be hidden while we swap from one update to the other
+      // to prevent restarting to update while staging is occurring. But since
+      // it will be waiting on the same event we are waiting on, wait an
+      // additional tick to let the other update-swap listeners run.
+      await TestUtils.waitForTick();
+
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "",
+        "Should not have restart badge during staging"
+      );
+
+      await continueFileHandler(CONTINUE_STAGING);
+
+      try {
+        await TestUtils.waitForCondition(
+          () =>
+            PanelUI.menuButton.getAttribute("badge-status") == "update-restart",
+          "Waiting for update restart badge to return after staging"
+        );
+      } catch (ex) {}
+
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "update-restart",
+        "Restart badge should be restored after staging completes"
+      );
+      is(
+        PanelUI.notificationPanel.state,
+        "closed",
+        "Should not open a second doorhanger"
+      );
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_multiUpdate_promptWaitTime.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_multiUpdate_promptWaitTime.js
new file mode 100644
index 0000000000..00c61bcbb4
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_multiUpdate_promptWaitTime.js
@@ -0,0 +1,89 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * This test downloads 2 updates sequentially, and ensures that the doorhanger
+ * and badge do what they are supposed to do. However, the first update has a
+ * long promptWaitTime, and the second has a short one and the badge wait time
+ * is set to 0. This should result in this behavior:
+ *   First thing after the first download, the badge should be displayed, but
+ *     not the doorhanger.
+ *   Then download the next update.
+ *   While that update stages, the badge should be hidden to prevent restarting
+ *     to update while the update is staging.
+ *   Once the staging completes, the doorhanger should be shown. Despite the
+ *     long promptWaitTime of the initial update, this patch's short wait time
+ *     means that the doorhanger should be shown soon rather than in a long
+ *     time.
+ */
+
+const FIRST_UPDATE_VERSION = "999998.0";
+const SECOND_UPDATE_VERSION = "999999.0";
+const LONG_PROMPT_WAIT_TIME_SEC = 10 * 60 * 60; // 10 hours
+
+function prepareToDownloadVersion(version, promptWaitTime) {
+  setUpdateURL(
+    URL_HTTP_UPDATE_SJS +
+      `?detailsURL=${gDetailsURL}&promptWaitTime=${promptWaitTime}&appVersion=${version}`
+  );
+}
+
+add_task(async function doorhanger_bc_multiUpdate() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      [PREF_APP_UPDATE_STAGING_ENABLED, true],
+      [PREF_APP_UPDATE_BADGEWAITTIME, 0],
+    ],
+  });
+
+  let params = {
+    checkAttempts: 1,
+    queryString: `&promptWaitTime=${LONG_PROMPT_WAIT_TIME_SEC}`,
+    version: FIRST_UPDATE_VERSION,
+    slowStaging: true,
+  };
+  await runDoorhangerUpdateTest(params, [
+    async () => {
+      await continueFileHandler(CONTINUE_STAGING);
+
+      try {
+        await TestUtils.waitForCondition(
+          () =>
+            PanelUI.menuButton.getAttribute("badge-status") == "update-restart",
+          "Waiting for update restart badge to return after staging"
+        );
+      } catch (ex) {}
+
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "update-restart",
+        "Should have restart badge"
+      );
+
+      prepareToDownloadVersion(SECOND_UPDATE_VERSION, 0);
+      let updateSwapped = waitForEvent("update-swap");
+      gAUS.checkForBackgroundUpdates();
+      await updateSwapped;
+      // The badge should be hidden while we swap from one update to the other
+      // to prevent restarting to update while staging is occurring. But since
+      // it will be waiting on the same event we are waiting on, wait an
+      // additional tick to let the other update-swap listeners run.
+      await TestUtils.waitForTick();
+
+      is(
+        PanelUI.menuButton.getAttribute("badge-status"),
+        "",
+        "Should not have restart badge during staging"
+      );
+
+      await continueFileHandler(CONTINUE_STAGING);
+    },
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_APPLIED },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_completeBadSize.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_completeBadSize.js
new file mode 100644
index 0000000000..3c29d6b4b0
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_completeBadSize.js
@@ -0,0 +1,33 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_patch_completeBadSize() {
+  let params = {
+    checkAttempts: 1,
+    queryString: "&completePatchOnly=1&invalidCompleteSize=1",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      // If the update download fails maxBackgroundErrors download attempts then
+      // show the update available prompt.
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      // If the update process is unable to install the update show the manual
+      // update doorhanger.
+      notificationId: "update-manual",
+      button: "button",
+      checkActiveUpdate: null,
+      pageURLs: { manual: URL_MANUAL_UPDATE },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_partialBadSize.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_partialBadSize.js
new file mode 100644
index 0000000000..68854b3f26
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_partialBadSize.js
@@ -0,0 +1,33 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_patch_partialBadSize() {
+  let params = {
+    checkAttempts: 1,
+    queryString: "&partialPatchOnly=1&invalidPartialSize=1",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      // If the update download fails maxBackgroundErrors download attempts then
+      // show the update available prompt.
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      // If the update process is unable to install the update show the manual
+      // update doorhanger.
+      notificationId: "update-manual",
+      button: "button",
+      checkActiveUpdate: null,
+      pageURLs: { manual: URL_MANUAL_UPDATE },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_partialBadSize_complete.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_partialBadSize_complete.js
new file mode 100644
index 0000000000..f3c9b1f51f
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_partialBadSize_complete.js
@@ -0,0 +1,18 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_patch_partialBadSize_complete() {
+  let params = {
+    checkAttempts: 1,
+    queryString: "&invalidPartialSize=1&promptWaitTime=0",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_PENDING },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_partialBadSize_completeBadSize.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_partialBadSize_completeBadSize.js
new file mode 100644
index 0000000000..a18e2f6444
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_bc_patch_partialBadSize_completeBadSize.js
@@ -0,0 +1,33 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_bc_patch_partialBadSize_completeBadSize() {
+  let params = {
+    checkAttempts: 1,
+    queryString: "&invalidPartialSize=1&invalidCompleteSize=1",
+  };
+  await runDoorhangerUpdateTest(params, [
+    {
+      // If the update download fails maxBackgroundErrors download attempts then
+      // show the update available prompt.
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      notificationId: "update-available",
+      button: "button",
+      checkActiveUpdate: null,
+    },
+    {
+      // If the update process is unable to install the update show the manual
+      // update doorhanger.
+      notificationId: "update-manual",
+      button: "button",
+      checkActiveUpdate: null,
+      pageURLs: { manual: URL_MANUAL_UPDATE },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_completeApplyFailure.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_completeApplyFailure.js
new file mode 100644
index 0000000000..5c7c937d81
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_completeApplyFailure.js
@@ -0,0 +1,23 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_sp_patch_completeApplyFailure() {
+  let patchProps = { state: STATE_PENDING };
+  let patches = getLocalPatchString(patchProps);
+  let updateProps = { checkInterval: "1" };
+  let updates = getLocalUpdateString(updateProps, patches);
+
+  let params = { updates };
+  await runDoorhangerUpdateTest(params, [
+    {
+      // If the update process is unable to install the update show the manual
+      // update doorhanger.
+      notificationId: "update-manual",
+      button: "button",
+      checkActiveUpdate: null,
+      pageURLs: { manual: URL_MANUAL_UPDATE },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure.js
new file mode 100644
index 0000000000..45434c8361
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure.js
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_sp_patch_partialApplyFailure() {
+  let patchProps = { type: "partial", state: STATE_PENDING };
+  let patches = getLocalPatchString(patchProps);
+  let updateProps = { isCompleteUpdate: "false", checkInterval: "1" };
+  let updates = getLocalUpdateString(updateProps, patches);
+
+  let params = { updates };
+  await runDoorhangerUpdateTest(params, [
+    {
+      // If there is only an invalid patch show the manual update doorhanger.
+      notificationId: "update-manual",
+      button: "button",
+      checkActiveUpdate: null,
+      pageURLs: { manual: URL_MANUAL_UPDATE },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure_complete.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure_complete.js
new file mode 100644
index 0000000000..bf533dab04
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure_complete.js
@@ -0,0 +1,22 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function doorhanger_sp_patch_partialApplyFailure_complete() {
+  let patchProps = { type: "partial", state: STATE_PENDING };
+  let patches = getLocalPatchString(patchProps);
+  patchProps = { selected: "false" };
+  patches += getLocalPatchString(patchProps);
+  let updateProps = { isCompleteUpdate: "false", promptWaitTime: "0" };
+  let updates = getLocalUpdateString(updateProps, patches);
+
+  let params = { updates };
+  await runDoorhangerUpdateTest(params, [
+    {
+      notificationId: "update-restart",
+      button: "secondaryButton",
+      checkActiveUpdate: { state: STATE_PENDING },
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure_completeBadSize.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure_completeBadSize.js
new file mode 100644
index 0000000000..df17bc1220
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure_completeBadSize.js
@@ -0,0 +1,32 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(
+  async function doorhanger_sp_patch_partialApplyFailure_completeBadSize() {
+    // Because of the way the test is simulating failure it has to pretend it has
+    // already retried.
+    await SpecialPowers.pushPrefEnv({
+      set: [[PREF_APP_UPDATE_DOWNLOAD_MAXATTEMPTS, 0]],
+    });
+
+    let patchProps = { type: "partial", state: STATE_PENDING };
+    let patches = getLocalPatchString(patchProps);
+    patchProps = { size: "1234", selected: "false" };
+    patches += getLocalPatchString(patchProps);
+    let updateProps = { isCompleteUpdate: "false" };
+    let updates = getLocalUpdateString(updateProps, patches);
+
+    let params = { updates };
+    await runDoorhangerUpdateTest(params, [
+      {
+        // If there is only an invalid patch show the manual update doorhanger.
+        notificationId: "update-manual",
+        button: "button",
+        checkActiveUpdate: null,
+        pageURLs: { manual: URL_MANUAL_UPDATE },
+      },
+    ]);
+  }
+);
diff --git a/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure_complete_staging.js b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure_complete_staging.js
new file mode 100644
index 0000000000..a99c04b0be
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_doorhanger_sp_patch_partialApplyFailure_complete_staging.js
@@ -0,0 +1,28 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(
+  async function doorhanger_sp_patch_partialApplyFailure_complete_staging() {
+    await SpecialPowers.pushPrefEnv({
+      set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+    });
+
+    let patchProps = { type: "partial", state: STATE_PENDING };
+    let patches = getLocalPatchString(patchProps);
+    patchProps = { selected: "false" };
+    patches += getLocalPatchString(patchProps);
+    let updateProps = { isCompleteUpdate: "false", promptWaitTime: "0" };
+    let updates = getLocalUpdateString(updateProps, patches);
+
+    let params = { updates };
+    await runDoorhangerUpdateTest(params, [
+      {
+        notificationId: "update-restart",
+        button: "secondaryButton",
+        checkActiveUpdate: { state: STATE_APPLIED },
+      },
+    ]);
+  }
+);
diff --git a/toolkit/mozapps/update/tests/browser/browser_elevationDialog.js b/toolkit/mozapps/update/tests/browser/browser_elevationDialog.js
new file mode 100644
index 0000000000..6aa32a7fc9
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_elevationDialog.js
@@ -0,0 +1,139 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function elevation_dialog() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_DISABLEDFORTESTING, false]],
+  });
+
+  // Create a mock of nsIAppStartup's quit method so clicking the restart button
+  // won't restart the application.
+  let { startup } = Services;
+  let appStartup = {
+    QueryInterface: ChromeUtils.generateQI(["nsIAppStartup"]),
+    quit(mode) {
+      if (elevationDialog) {
+        elevationDialog.close();
+        elevationDialog = null;
+      }
+    },
+  };
+  Services.startup = appStartup;
+  registerCleanupFunction(() => {
+    Services.startup = startup;
+  });
+
+  registerCleanupFunction(async () => {
+    let win = Services.wm.getMostRecentWindow("Update:Elevation");
+    if (win) {
+      win.close();
+      await TestUtils.waitForCondition(
+        () => !Services.wm.getMostRecentWindow("Update:Elevation"),
+        "The Update Elevation dialog should have closed"
+      );
+    }
+  });
+
+  // Test clicking the "Restart Later" button
+  let elevationDialog = await waitForElevationDialog();
+  await TestUtils.waitForTick();
+  elevationDialog.document.getElementById("elevateExtra2").click();
+  await TestUtils.waitForCondition(
+    () => !Services.wm.getMostRecentWindow("Update:Elevation"),
+    "The Update Elevation dialog should have closed"
+  );
+  ok(!!gUpdateManager.readyUpdate, "There should be a ready update");
+  is(
+    gUpdateManager.readyUpdate.state,
+    STATE_PENDING_ELEVATE,
+    "The ready update state should equal " + STATE_PENDING_ELEVATE
+  );
+  is(
+    readStatusFile(),
+    STATE_PENDING_ELEVATE,
+    "The status file state should equal " + STATE_PENDING_ELEVATE
+  );
+
+  // Test clicking the "No Thanks" button
+  elevationDialog = await waitForElevationDialog();
+  await TestUtils.waitForTick();
+  elevationDialog.document.getElementById("elevateExtra1").click();
+  await TestUtils.waitForCondition(
+    () => !Services.wm.getMostRecentWindow("Update:Elevation"),
+    "The Update Elevation dialog should have closed"
+  );
+  ok(!gUpdateManager.readyUpdate, "There should not be a ready update");
+  is(
+    readStatusFile(),
+    STATE_NONE,
+    "The status file state should equal " + STATE_NONE
+  );
+
+  // Test clicking the "Restart <brandShortName>" button
+  elevationDialog = await waitForElevationDialog();
+  await TestUtils.waitForTick();
+  elevationDialog.document.getElementById("elevateAccept").click();
+  await TestUtils.waitForCondition(
+    () => !Services.wm.getMostRecentWindow("Update:Elevation"),
+    "The Update Elevation dialog should have closed"
+  );
+  ok(!!gUpdateManager.readyUpdate, "There should be a ready update");
+  is(
+    gUpdateManager.readyUpdate.state,
+    STATE_PENDING_ELEVATE,
+    "The active update state should equal " + STATE_PENDING_ELEVATE
+  );
+  is(
+    readStatusFile(),
+    STATE_PENDING,
+    "The status file state should equal " + STATE_PENDING
+  );
+});
+
+/**
+ * Waits for the Update Elevation Dialog to load.
+ *
+ * @return A promise that returns the domWindow for the Update Elevation Dialog
+ *         and resolves when the Update Elevation Dialog loads.
+ */
+function waitForElevationDialog() {
+  return new Promise(resolve => {
+    var listener = {
+      onOpenWindow: aXULWindow => {
+        debugDump("Update Elevation dialog shown...");
+        Services.wm.removeListener(listener);
+
+        async function elevationDialogOnLoad() {
+          domwindow.removeEventListener("load", elevationDialogOnLoad, true);
+          let chromeURI =
+            "chrome://mozapps/content/update/updateElevation.xhtml";
+          is(
+            domwindow.document.location.href,
+            chromeURI,
+            "Update Elevation appeared"
+          );
+          resolve(domwindow);
+        }
+
+        var domwindow = aXULWindow.docShell.domWindow;
+        domwindow.addEventListener("load", elevationDialogOnLoad, true);
+      },
+      onCloseWindow: aXULWindow => {},
+    };
+
+    Services.wm.addListener(listener);
+    // Add the active-update.xml and update.status files used for these tests,
+    // reload the update manager, and then simulate startup so the Update
+    // Elevation Dialog is opened.
+    let patchProps = { state: STATE_PENDING_ELEVATE };
+    let patches = getLocalPatchString(patchProps);
+    let updateProps = { checkInterval: "1" };
+    let updates = getLocalUpdateString(updateProps, patches);
+    writeUpdatesToXMLFile(getLocalUpdatesXMLString(updates), true);
+    writeStatusFile(STATE_PENDING_ELEVATE);
+    reloadUpdateManagerData();
+    testPostUpdateProcessing();
+  });
+}
diff --git a/toolkit/mozapps/update/tests/browser/browser_memory_allocation_error_fallback.js b/toolkit/mozapps/update/tests/browser/browser_memory_allocation_error_fallback.js
new file mode 100644
index 0000000000..55ec2e14a1
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_memory_allocation_error_fallback.js
@@ -0,0 +1,81 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * When the updater fails with a memory allocation error, we should fall back to
+ * updating without staging.
+ */
+
+const READ_STRINGS_MEM_ERROR = 10;
+const ARCHIVE_READER_MEM_ERROR = 11;
+const BSPATCH_MEM_ERROR = 12;
+const UPDATER_MEM_ERROR = 13;
+const UPDATER_QUOTED_PATH_MEM_ERROR = 14;
+
+const EXPECTED_STATUS =
+  AppConstants.platform == "win" ? STATE_PENDING_SVC : STATE_PENDING;
+
+add_setup(async function setup() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      [PREF_APP_UPDATE_STAGING_ENABLED, true],
+      [PREF_APP_UPDATE_SERVICE_ENABLED, true],
+    ],
+  });
+
+  registerCleanupFunction(() => {
+    Services.env.set("MOZ_FORCE_ERROR_CODE", "");
+  });
+});
+
+async function memAllocErrorFallback(errorCode) {
+  Services.env.set("MOZ_FORCE_ERROR_CODE", errorCode.toString());
+
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = {
+    queryString: "&invalidCompleteSize=1",
+    backgroundUpdate: true,
+    continueFile: CONTINUE_STAGING,
+    waitForUpdateState: EXPECTED_STATUS,
+  };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: EXPECTED_STATUS },
+      continueFile: null,
+    },
+  ]);
+}
+
+function cleanup() {
+  reloadUpdateManagerData(true);
+  removeUpdateFiles(true);
+}
+
+add_task(async function memAllocErrorFallback_READ_STRINGS_MEM_ERROR() {
+  await memAllocErrorFallback(READ_STRINGS_MEM_ERROR);
+  cleanup();
+});
+
+add_task(async function memAllocErrorFallback_ARCHIVE_READER_MEM_ERROR() {
+  await memAllocErrorFallback(ARCHIVE_READER_MEM_ERROR);
+  cleanup();
+});
+
+add_task(async function memAllocErrorFallback_BSPATCH_MEM_ERROR() {
+  await memAllocErrorFallback(BSPATCH_MEM_ERROR);
+  cleanup();
+});
+
+add_task(async function memAllocErrorFallback_UPDATER_MEM_ERROR() {
+  await memAllocErrorFallback(UPDATER_MEM_ERROR);
+  cleanup();
+});
+
+add_task(async function memAllocErrorFallback_UPDATER_QUOTED_PATH_MEM_ERROR() {
+  await memAllocErrorFallback(UPDATER_QUOTED_PATH_MEM_ERROR);
+  cleanup();
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_telemetry_updatePing_downloaded_ready.js b/toolkit/mozapps/update/tests/browser/browser_telemetry_updatePing_downloaded_ready.js
new file mode 100644
index 0000000000..f9045bbdda
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_telemetry_updatePing_downloaded_ready.js
@@ -0,0 +1,68 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { TelemetryArchiveTesting } = ChromeUtils.importESModule(
+  "resource://testing-common/TelemetryArchiveTesting.sys.mjs"
+);
+
+/**
+ * Test that UpdatePing telemetry with a payload reason of ready is sent for a
+ * staged update.
+ *
+ * Please note that this is really a Telemetry test, not an
+ * "update UI" test like the rest of the tests in this directory.
+ * This test does not live in toolkit/components/telemetry/tests to prevent
+ * duplicating the code for all the test dependencies. Unfortunately, due
+ * to a limitation in the build system, we were not able to simply reference
+ * the dependencies as "support-files" in the test manifest.
+ */
+add_task(async function telemetry_updatePing_ready() {
+  let archiveChecker = new TelemetryArchiveTesting.Checker();
+  await archiveChecker.promiseInit();
+
+  let updateParams = "";
+  await runTelemetryUpdateTest(updateParams, "update-downloaded");
+
+  // We cannot control when the ping will be generated/archived after we trigger
+  // an update, so let's make sure to have one before moving on with validation.
+  let updatePing;
+  await TestUtils.waitForCondition(
+    async function () {
+      // Check that the ping made it into the Telemetry archive.
+      // The test data is defined in ../data/sharedUpdateXML.js
+      updatePing = await archiveChecker.promiseFindPing("update", [
+        [["payload", "reason"], "ready"],
+        [["payload", "targetBuildId"], "20080811053724"],
+      ]);
+      return !!updatePing;
+    },
+    "Make sure the ping is generated before trying to validate it.",
+    500,
+    100
+  );
+
+  ok(updatePing, "The 'update' ping must be correctly sent.");
+
+  // We don't know the exact value for the other fields, so just check
+  // that they're available.
+  for (let f of ["targetVersion", "targetChannel", "targetDisplayVersion"]) {
+    ok(
+      f in updatePing.payload,
+      `${f} must be available in the update ping payload.`
+    );
+    ok(
+      typeof updatePing.payload[f] == "string",
+      `${f} must have the correct format.`
+    );
+  }
+
+  // Also make sure that the ping contains both a client id and an
+  // environment section.
+  ok("clientId" in updatePing, "The update ping must report a client id.");
+  ok(
+    "environment" in updatePing,
+    "The update ping must report the environment."
+  );
+});
diff --git a/toolkit/mozapps/update/tests/browser/browser_telemetry_updatePing_staged_ready.js b/toolkit/mozapps/update/tests/browser/browser_telemetry_updatePing_staged_ready.js
new file mode 100644
index 0000000000..42bd0da546
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/browser_telemetry_updatePing_staged_ready.js
@@ -0,0 +1,72 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const { TelemetryArchiveTesting } = ChromeUtils.importESModule(
+  "resource://testing-common/TelemetryArchiveTesting.sys.mjs"
+);
+
+/**
+ * Test that UpdatePing telemetry with a payload reason of ready is sent for a
+ * staged update.
+ *
+ * Please note that this is really a Telemetry test, not an
+ * "update UI" test like the rest of the tests in this directory.
+ * This test does not live in toolkit/components/telemetry/tests to prevent
+ * duplicating the code for all the test dependencies. Unfortunately, due
+ * to a limitation in the build system, we were not able to simply reference
+ * the dependencies as "support-files" in the test manifest.
+ */
+add_task(async function telemetry_updatePing_ready() {
+  await SpecialPowers.pushPrefEnv({
+    set: [[PREF_APP_UPDATE_STAGING_ENABLED, true]],
+  });
+
+  let archiveChecker = new TelemetryArchiveTesting.Checker();
+  await archiveChecker.promiseInit();
+
+  let updateParams = "";
+  await runTelemetryUpdateTest(updateParams, "update-staged");
+
+  // We cannot control when the ping will be generated/archived after we trigger
+  // an update, so let's make sure to have one before moving on with validation.
+  let updatePing;
+  await TestUtils.waitForCondition(
+    async function () {
+      // Check that the ping made it into the Telemetry archive.
+      // The test data is defined in ../data/sharedUpdateXML.js
+      updatePing = await archiveChecker.promiseFindPing("update", [
+        [["payload", "reason"], "ready"],
+        [["payload", "targetBuildId"], "20080811053724"],
+      ]);
+      return !!updatePing;
+    },
+    "Make sure the ping is generated before trying to validate it.",
+    500,
+    100
+  );
+
+  ok(updatePing, "The 'update' ping must be correctly sent.");
+
+  // We don't know the exact value for the other fields, so just check
+  // that they're available.
+  for (let f of ["targetVersion", "targetChannel", "targetDisplayVersion"]) {
+    ok(
+      f in updatePing.payload,
+      `${f} must be available in the update ping payload.`
+    );
+    ok(
+      typeof updatePing.payload[f] == "string",
+      `${f} must have the correct format.`
+    );
+  }
+
+  // Also make sure that the ping contains both a client id and an
+  // environment section.
+  ok("clientId" in updatePing, "The update ping must report a client id.");
+  ok(
+    "environment" in updatePing,
+    "The update ping must report the environment."
+  );
+});
diff --git a/toolkit/mozapps/update/tests/browser/downloadPage.html b/toolkit/mozapps/update/tests/browser/downloadPage.html
new file mode 100644
index 0000000000..4810e2e0d6
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/downloadPage.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <title>Download page</title>
+  <meta charset="utf-8">
+</head>
+<body>
+<!-- just use simple.mar since we have it available and it will result in a download dialog -->
+<a id="download-link" href="http://example.com/browser/browser/base/content/test/appUpdate/simple.mar" data-link-type="download">
+  Download
+</a>
+</body>
+</html>
diff --git a/toolkit/mozapps/update/tests/browser/head.js b/toolkit/mozapps/update/tests/browser/head.js
new file mode 100644
index 0000000000..756b2c7ea5
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/head.js
@@ -0,0 +1,1347 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+ChromeUtils.defineESModuleGetters(this, {
+  AppMenuNotifications: "resource://gre/modules/AppMenuNotifications.sys.mjs",
+  DownloadUtils: "resource://gre/modules/DownloadUtils.sys.mjs",
+  UpdateListener: "resource://gre/modules/UpdateListener.sys.mjs",
+});
+const { XPIInstall } = ChromeUtils.import(
+  "resource://gre/modules/addons/XPIInstall.jsm"
+);
+
+const BIN_SUFFIX = AppConstants.platform == "win" ? ".exe" : "";
+const FILE_UPDATER_BIN =
+  "updater" + (AppConstants.platform == "macosx" ? ".app" : BIN_SUFFIX);
+const FILE_UPDATER_BIN_BAK = FILE_UPDATER_BIN + ".bak";
+
+const LOG_FUNCTION = info;
+
+const MAX_UPDATE_COPY_ATTEMPTS = 10;
+
+const DATA_URI_SPEC =
+  "chrome://mochitests/content/browser/toolkit/mozapps/update/tests/browser/";
+/* import-globals-from testConstants.js */
+Services.scriptloader.loadSubScript(DATA_URI_SPEC + "testConstants.js", this);
+
+var gURLData = URL_HOST + "/" + REL_PATH_DATA;
+const URL_MANUAL_UPDATE = gURLData + "downloadPage.html";
+
+const gBadSizeResult = Cr.NS_ERROR_UNEXPECTED.toString();
+
+/* import-globals-from ../data/shared.js */
+Services.scriptloader.loadSubScript(DATA_URI_SPEC + "shared.js", this);
+
+let gOriginalUpdateAutoValue = null;
+
+// Some elements append a trailing /. After the chrome tests are removed this
+// code can be changed so URL_HOST already has a trailing /.
+const gDetailsURL = URL_HOST + "/";
+
+// Set to true to log additional information for debugging. To log additional
+// information for individual tests set gDebugTest to false here and to true
+// globally in the test.
+gDebugTest = false;
+
+// This is to accommodate the TV task which runs the tests with --verify.
+requestLongerTimeout(10);
+
+/**
+ * Common tasks to perform for all tests before each one has started.
+ */
+add_setup(async function setupTestCommon() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      [PREF_APP_UPDATE_BADGEWAITTIME, 1800],
+      [PREF_APP_UPDATE_DOWNLOAD_ATTEMPTS, 0],
+      [PREF_APP_UPDATE_DOWNLOAD_MAXATTEMPTS, 2],
+      [PREF_APP_UPDATE_LOG, gDebugTest],
+      [PREF_APP_UPDATE_PROMPTWAITTIME, 3600],
+      [PREF_APP_UPDATE_SERVICE_ENABLED, false],
+    ],
+  });
+
+  // We need to keep the update sync manager from thinking two instances are
+  // running because of the mochitest parent instance, which means we need to
+  // override the directory service with a fake executable path and then reset
+  // the lock. But leaving the directory service overridden causes problems for
+  // these tests, so we need to restore the real service immediately after.
+  // To form the path, we'll use the real executable path with a token appended
+  // (the path needs to be absolute, but not to point to a real file).
+  // This block is loosely copied from adjustGeneralPaths() in another update
+  // test file, xpcshellUtilsAUS.js, but this is a much more limited version;
+  // it's been copied here both because the full function is overkill and also
+  // because making it general enough to run in both xpcshell and mochitest
+  // would have been unreasonably difficult.
+  let exePath = Services.dirsvc.get(XRE_EXECUTABLE_FILE, Ci.nsIFile);
+  let dirProvider = {
+    getFile: function AGP_DP_getFile(aProp, aPersistent) {
+      // Set the value of persistent to false so when this directory provider is
+      // unregistered it will revert back to the original provider.
+      aPersistent.value = false;
+      switch (aProp) {
+        case XRE_EXECUTABLE_FILE:
+          exePath.append("browser-test");
+          return exePath;
+      }
+      return null;
+    },
+    QueryInterface: ChromeUtils.generateQI(["nsIDirectoryServiceProvider"]),
+  };
+  let ds = Services.dirsvc.QueryInterface(Ci.nsIDirectoryService);
+  ds.QueryInterface(Ci.nsIProperties).undefine(XRE_EXECUTABLE_FILE);
+  ds.registerProvider(dirProvider);
+
+  let syncManager = Cc["@mozilla.org/updates/update-sync-manager;1"].getService(
+    Ci.nsIUpdateSyncManager
+  );
+  syncManager.resetLock();
+
+  ds.unregisterProvider(dirProvider);
+
+  setUpdateTimerPrefs();
+  reloadUpdateManagerData(true);
+  removeUpdateFiles(true);
+  UpdateListener.reset();
+  AppMenuNotifications.removeNotification(/.*/);
+  // Most app update mochitest-browser-chrome tests expect auto update to be
+  // enabled. Those that don't will explicitly change this.
+  await setAppUpdateAutoEnabledHelper(true);
+});
+
+/**
+ * Common tasks to perform for all tests after each one has finished.
+ */
+registerCleanupFunction(async () => {
+  AppMenuNotifications.removeNotification(/.*/);
+  Services.env.set("MOZ_TEST_SKIP_UPDATE_STAGE", "");
+  Services.env.set("MOZ_TEST_SLOW_SKIP_UPDATE_STAGE", "");
+  Services.env.set("MOZ_TEST_STAGING_ERROR", "");
+  UpdateListener.reset();
+  AppMenuNotifications.removeNotification(/.*/);
+  reloadUpdateManagerData(true);
+  // Pass false when the log files are needed for troubleshooting the tests.
+  removeUpdateFiles(true);
+  // Always try to restore the original updater files. If none of the updater
+  // backup files are present then this is just a no-op.
+  await finishTestRestoreUpdaterBackup();
+  // Reset the update lock once again so that we know the lock we're
+  // interested in here will be closed properly (normally that happens during
+  // XPCOM shutdown, but that isn't consistent during tests).
+  let syncManager = Cc["@mozilla.org/updates/update-sync-manager;1"].getService(
+    Ci.nsIUpdateSyncManager
+  );
+  syncManager.resetLock();
+});
+
+/**
+ * Overrides the add-ons manager language pack staging with a mocked version.
+ * The returned promise resolves when language pack staging begins returning an
+ * object with the new appVersion and platformVersion and functions to resolve
+ * or reject the install.
+ */
+function mockLangpackInstall() {
+  let original = XPIInstall.stageLangpacksForAppUpdate;
+  registerCleanupFunction(() => {
+    XPIInstall.stageLangpacksForAppUpdate = original;
+  });
+
+  let stagingCall = PromiseUtils.defer();
+  XPIInstall.stageLangpacksForAppUpdate = (appVersion, platformVersion) => {
+    let result = PromiseUtils.defer();
+    stagingCall.resolve({
+      appVersion,
+      platformVersion,
+      resolve: result.resolve,
+      reject: result.reject,
+    });
+
+    return result.promise;
+  };
+
+  return stagingCall.promise;
+}
+
+/**
+ * Creates and locks the app update write test file so it is possible to test
+ * when the user doesn't have write access to update. Since this is only
+ * possible on Windows the function throws when it is called on other platforms.
+ * This uses registerCleanupFunction to remove the lock and the file when the
+ * test completes.
+ *
+ * @throws If the function is called on a platform other than Windows.
+ */
+function lockWriteTestFile() {
+  if (AppConstants.platform != "win") {
+    throw new Error("Windows only test function called");
+  }
+  let file = getUpdateDirFile(FILE_UPDATE_TEST).QueryInterface(
+    Ci.nsILocalFileWin
+  );
+  // Remove the file if it exists just in case.
+  if (file.exists()) {
+    file.readOnly = false;
+    file.remove(false);
+  }
+  file.create(file.NORMAL_FILE_TYPE, 0o444);
+  file.readOnly = true;
+  registerCleanupFunction(() => {
+    file.readOnly = false;
+    file.remove(false);
+  });
+}
+
+/**
+ * Closes the update mutex handle in nsUpdateService.js if it exists and then
+ * creates a new update mutex handle so the update code thinks there is another
+ * instance of the application handling updates.
+ *
+ * @throws If the function is called on a platform other than Windows.
+ */
+function setOtherInstanceHandlingUpdates() {
+  if (AppConstants.platform != "win") {
+    throw new Error("Windows only test function called");
+  }
+  gAUS.observe(null, "test-close-handle-update-mutex", "");
+  let handle = createMutex(getPerInstallationMutexName());
+  registerCleanupFunction(() => {
+    closeHandle(handle);
+  });
+}
+
+/**
+ * Gets the update version info for the update url parameters to send to
+ * app_update.sjs.
+ *
+ * @param  aAppVersion (optional)
+ *         The application version for the update snippet. If not specified the
+ *         current application version will be used.
+ * @return The url parameters for the application and platform version to send
+ *         to app_update.sjs.
+ */
+function getVersionParams(aAppVersion) {
+  let appInfo = Services.appinfo;
+  return "&appVersion=" + (aAppVersion ? aAppVersion : appInfo.version);
+}
+
+/**
+ * Prevent nsIUpdateTimerManager from notifying nsIApplicationUpdateService
+ * to check for updates by setting the app update last update time to the
+ * current time minus one minute in seconds and the interval time to 12 hours
+ * in seconds.
+ */
+function setUpdateTimerPrefs() {
+  let now = Math.round(Date.now() / 1000) - 60;
+  Services.prefs.setIntPref(PREF_APP_UPDATE_LASTUPDATETIME, now);
+  Services.prefs.setIntPref(PREF_APP_UPDATE_INTERVAL, 43200);
+}
+
+/*
+ * Sets the value of the App Auto Update setting and sets it back to the
+ * original value at the start of the test when the test finishes.
+ *
+ * @param  enabled
+ *         The value to set App Auto Update to.
+ */
+async function setAppUpdateAutoEnabledHelper(enabled) {
+  if (gOriginalUpdateAutoValue == null) {
+    gOriginalUpdateAutoValue = await UpdateUtils.getAppUpdateAutoEnabled();
+    registerCleanupFunction(async () => {
+      await UpdateUtils.setAppUpdateAutoEnabled(gOriginalUpdateAutoValue);
+    });
+  }
+  await UpdateUtils.setAppUpdateAutoEnabled(enabled);
+}
+
+/**
+ * Gets the specified button for the notification.
+ *
+ * @param  win
+ *         The window to get the notification button for.
+ * @param  notificationId
+ *         The ID of the notification to get the button for.
+ * @param  button
+ *         The anonid of the button to get.
+ * @return The button element.
+ */
+function getNotificationButton(win, notificationId, button) {
+  let notification = win.document.getElementById(
+    `appMenu-${notificationId}-notification`
+  );
+  ok(!notification.hidden, `${notificationId} notification is showing`);
+  return notification[button];
+}
+
+/**
+ * For staging tests the test updater must be used and this restores the backed
+ * up real updater if it exists and tries again on failure since Windows debug
+ * builds at times leave the file in use. After success moveRealUpdater is
+ * called to continue the setup of the test updater.
+ */
+function setupTestUpdater() {
+  return (async function () {
+    if (Services.prefs.getBoolPref(PREF_APP_UPDATE_STAGING_ENABLED)) {
+      try {
+        restoreUpdaterBackup();
+      } catch (e) {
+        logTestInfo(
+          "Attempt to restore the backed up updater failed... " +
+            "will try again, Exception: " +
+            e
+        );
+        await TestUtils.waitForTick();
+        await setupTestUpdater();
+        return;
+      }
+      await moveRealUpdater();
+    }
+  })();
+}
+
+/**
+ * Backs up the real updater and tries again on failure since Windows debug
+ * builds at times leave the file in use. After success it will call
+ * copyTestUpdater to continue the setup of the test updater.
+ */
+function moveRealUpdater() {
+  return (async function () {
+    try {
+      // Move away the real updater
+      let greBinDir = getGREBinDir();
+      let updater = greBinDir.clone();
+      updater.append(FILE_UPDATER_BIN);
+      updater.moveTo(greBinDir, FILE_UPDATER_BIN_BAK);
+
+      let greDir = getGREDir();
+      let updateSettingsIni = greDir.clone();
+      updateSettingsIni.append(FILE_UPDATE_SETTINGS_INI);
+      if (updateSettingsIni.exists()) {
+        updateSettingsIni.moveTo(greDir, FILE_UPDATE_SETTINGS_INI_BAK);
+      }
+
+      let precomplete = greDir.clone();
+      precomplete.append(FILE_PRECOMPLETE);
+      if (precomplete.exists()) {
+        precomplete.moveTo(greDir, FILE_PRECOMPLETE_BAK);
+      }
+    } catch (e) {
+      logTestInfo(
+        "Attempt to move the real updater out of the way failed... " +
+          "will try again, Exception: " +
+          e
+      );
+      await TestUtils.waitForTick();
+      await moveRealUpdater();
+      return;
+    }
+
+    await copyTestUpdater();
+  })();
+}
+
+/**
+ * Copies the test updater and tries again on failure since Windows debug builds
+ * at times leave the file in use.
+ */
+function copyTestUpdater(attempt = 0) {
+  return (async function () {
+    try {
+      // Copy the test updater
+      let greBinDir = getGREBinDir();
+      let testUpdaterDir = Services.dirsvc.get("CurWorkD", Ci.nsIFile);
+      let relPath = REL_PATH_DATA;
+      let pathParts = relPath.split("/");
+      for (let i = 0; i < pathParts.length; ++i) {
+        testUpdaterDir.append(pathParts[i]);
+      }
+
+      let testUpdater = testUpdaterDir.clone();
+      testUpdater.append(FILE_UPDATER_BIN);
+      testUpdater.copyToFollowingLinks(greBinDir, FILE_UPDATER_BIN);
+
+      let greDir = getGREDir();
+      let updateSettingsIni = greDir.clone();
+      updateSettingsIni.append(FILE_UPDATE_SETTINGS_INI);
+      writeFile(updateSettingsIni, UPDATE_SETTINGS_CONTENTS);
+
+      let precomplete = greDir.clone();
+      precomplete.append(FILE_PRECOMPLETE);
+      writeFile(precomplete, PRECOMPLETE_CONTENTS);
+    } catch (e) {
+      if (attempt < MAX_UPDATE_COPY_ATTEMPTS) {
+        logTestInfo(
+          "Attempt to copy the test updater failed... " +
+            "will try again, Exception: " +
+            e
+        );
+        await TestUtils.waitForTick();
+        await copyTestUpdater(attempt++);
+      }
+    }
+  })();
+}
+
+/**
+ * Restores the updater and updater related file that if there a backup exists.
+ * This is called in setupTestUpdater before the backup of the real updater is
+ * done in case the previous test failed to restore the file when a test has
+ * finished. This is also called in finishTestRestoreUpdaterBackup to restore
+ * the files when a test finishes.
+ */
+function restoreUpdaterBackup() {
+  let greBinDir = getGREBinDir();
+  let updater = greBinDir.clone();
+  let updaterBackup = greBinDir.clone();
+  updater.append(FILE_UPDATER_BIN);
+  updaterBackup.append(FILE_UPDATER_BIN_BAK);
+  if (updaterBackup.exists()) {
+    if (updater.exists()) {
+      updater.remove(true);
+    }
+    updaterBackup.moveTo(greBinDir, FILE_UPDATER_BIN);
+  }
+
+  let greDir = getGREDir();
+  let updateSettingsIniBackup = greDir.clone();
+  updateSettingsIniBackup.append(FILE_UPDATE_SETTINGS_INI_BAK);
+  if (updateSettingsIniBackup.exists()) {
+    let updateSettingsIni = greDir.clone();
+    updateSettingsIni.append(FILE_UPDATE_SETTINGS_INI);
+    if (updateSettingsIni.exists()) {
+      updateSettingsIni.remove(false);
+    }
+    updateSettingsIniBackup.moveTo(greDir, FILE_UPDATE_SETTINGS_INI);
+  }
+
+  let precomplete = greDir.clone();
+  let precompleteBackup = greDir.clone();
+  precomplete.append(FILE_PRECOMPLETE);
+  precompleteBackup.append(FILE_PRECOMPLETE_BAK);
+  if (precompleteBackup.exists()) {
+    if (precomplete.exists()) {
+      precomplete.remove(false);
+    }
+    precompleteBackup.moveTo(greDir, FILE_PRECOMPLETE);
+  } else if (precomplete.exists()) {
+    if (readFile(precomplete) == PRECOMPLETE_CONTENTS) {
+      precomplete.remove(false);
+    }
+  }
+}
+
+/**
+ * When a test finishes this will repeatedly attempt to restore the real updater
+ * and the other files for the updater if a backup of the file exists.
+ */
+function finishTestRestoreUpdaterBackup() {
+  return (async function () {
+    try {
+      // Windows debug builds keep the updater file in use for a short period of
+      // time after the updater process exits.
+      restoreUpdaterBackup();
+    } catch (e) {
+      logTestInfo(
+        "Attempt to restore the backed up updater failed... " +
+          "will try again, Exception: " +
+          e
+      );
+
+      await TestUtils.waitForTick();
+      await finishTestRestoreUpdaterBackup();
+    }
+  })();
+}
+
+/**
+ * Waits for the About Dialog to load.
+ *
+ * @return A promise that returns the domWindow for the About Dialog and
+ *         resolves when the About Dialog loads.
+ */
+function waitForAboutDialog() {
+  return new Promise(resolve => {
+    var listener = {
+      onOpenWindow: aXULWindow => {
+        debugDump("About dialog shown...");
+        Services.wm.removeListener(listener);
+
+        async function aboutDialogOnLoad() {
+          domwindow.removeEventListener("load", aboutDialogOnLoad, true);
+          let chromeURI = "chrome://browser/content/aboutDialog.xhtml";
+          is(
+            domwindow.document.location.href,
+            chromeURI,
+            "About dialog appeared"
+          );
+          resolve(domwindow);
+        }
+
+        var domwindow = aXULWindow.docShell.domWindow;
+        domwindow.addEventListener("load", aboutDialogOnLoad, true);
+      },
+      onCloseWindow: aXULWindow => {},
+    };
+
+    Services.wm.addListener(listener);
+    openAboutDialog();
+  });
+}
+
+/**
+ * Return the first UpdatePatch with the given type.
+ *
+ * @param   type
+ *          The type of the patch ("complete" or "partial")
+ * @param   update
+ *          The nsIUpdate to select a patch from.
+ * @return  A nsIUpdatePatch object matching the type specified
+ */
+function getPatchOfType(type, update) {
+  if (update) {
+    for (let i = 0; i < update.patchCount; ++i) {
+      let patch = update.getPatchAt(i);
+      if (patch && patch.type == type) {
+        return patch;
+      }
+    }
+  }
+  return null;
+}
+
+/**
+ * Runs a Doorhanger update test. This will set various common prefs for
+ * updating and runs the provided list of steps.
+ *
+ * @param  params
+ *         An object containing parameters used to run the test.
+ * @param  steps
+ *         An array of test steps to perform. A step will either be an object
+ *         containing expected conditions and actions or a function to call.
+ * @return A promise which will resolve once all of the steps have been run.
+ */
+function runDoorhangerUpdateTest(params, steps) {
+  function processDoorhangerStep(step) {
+    if (typeof step == "function") {
+      return step();
+    }
+
+    const {
+      notificationId,
+      button,
+      checkActiveUpdate,
+      pageURLs,
+      expectedStateOverride,
+    } = step;
+    return (async function () {
+      if (!params.popupShown && !PanelUI.isNotificationPanelOpen) {
+        await BrowserTestUtils.waitForEvent(
+          PanelUI.notificationPanel,
+          "popupshown"
+        );
+      }
+      const shownNotificationId = AppMenuNotifications.activeNotification.id;
+      is(
+        shownNotificationId,
+        notificationId,
+        "The right notification showed up."
+      );
+
+      let expectedState = Ci.nsIApplicationUpdateService.STATE_IDLE;
+      if (expectedStateOverride) {
+        expectedState = expectedStateOverride;
+      } else if (notificationId == "update-restart") {
+        expectedState = Ci.nsIApplicationUpdateService.STATE_PENDING;
+      }
+      let actualState = gAUS.currentState;
+      is(
+        actualState,
+        expectedState,
+        `The current update state should be ` +
+          `"${gAUS.getStateName(expectedState)}". Actual: ` +
+          `"${gAUS.getStateName(actualState)}"`
+      );
+
+      if (checkActiveUpdate) {
+        let activeUpdate =
+          checkActiveUpdate.state == STATE_DOWNLOADING
+            ? gUpdateManager.downloadingUpdate
+            : gUpdateManager.readyUpdate;
+        ok(!!activeUpdate, "There should be an active update");
+        is(
+          activeUpdate.state,
+          checkActiveUpdate.state,
+          `The active update state should equal ${checkActiveUpdate.state}`
+        );
+      } else {
+        ok(
+          !gUpdateManager.downloadingUpdate,
+          "There should not be a downloading update"
+        );
+        ok(!gUpdateManager.readyUpdate, "There should not be a ready update");
+      }
+
+      let buttonEl = getNotificationButton(window, notificationId, button);
+      buttonEl.click();
+
+      if (pageURLs && pageURLs.manual !== undefined) {
+        await BrowserTestUtils.browserLoaded(gBrowser.selectedBrowser);
+        is(
+          gBrowser.selectedBrowser.currentURI.spec,
+          pageURLs.manual,
+          `The page's url should equal ${pageURLs.manual}`
+        );
+        gBrowser.removeTab(gBrowser.selectedTab);
+      }
+    })();
+  }
+
+  return (async function () {
+    if (params.slowStaging) {
+      Services.env.set("MOZ_TEST_SLOW_SKIP_UPDATE_STAGE", "1");
+    } else {
+      Services.env.set("MOZ_TEST_SKIP_UPDATE_STAGE", "1");
+    }
+    await SpecialPowers.pushPrefEnv({
+      set: [
+        [PREF_APP_UPDATE_DISABLEDFORTESTING, false],
+        [PREF_APP_UPDATE_URL_DETAILS, gDetailsURL],
+        [PREF_APP_UPDATE_URL_MANUAL, URL_MANUAL_UPDATE],
+      ],
+    });
+
+    await setupTestUpdater();
+
+    let baseURL = URL_HTTP_UPDATE_SJS;
+    if (params.baseURL) {
+      baseURL = params.baseURL;
+    }
+    let queryString = params.queryString ? params.queryString : "";
+    let updateURL =
+      baseURL +
+      "?detailsURL=" +
+      gDetailsURL +
+      queryString +
+      getVersionParams(params.version);
+    setUpdateURL(updateURL);
+    if (params.checkAttempts) {
+      // Perform a background check doorhanger test.
+      executeSoon(() => {
+        (async function () {
+          gAUS.checkForBackgroundUpdates();
+          for (var i = 0; i < params.checkAttempts - 1; i++) {
+            await waitForEvent("update-error", "check-attempt-failed");
+            gAUS.checkForBackgroundUpdates();
+          }
+        })();
+      });
+    } else {
+      // Perform a startup processing doorhanger test.
+      writeStatusFile(STATE_FAILED_CRC_ERROR);
+      writeUpdatesToXMLFile(getLocalUpdatesXMLString(params.updates), true);
+      reloadUpdateManagerData();
+      testPostUpdateProcessing();
+    }
+
+    for (let step of steps) {
+      await processDoorhangerStep(step);
+    }
+  })();
+}
+
+/**
+ * Runs an About Dialog update test. This will set various common prefs for
+ * updating and runs the provided list of steps.
+ *
+ * @param  params
+ *         An object containing parameters used to run the test.
+ * @param  steps
+ *         An array of test steps to perform. A step will either be an object
+ *         containing expected conditions and actions or a function to call.
+ * @return A promise which will resolve once all of the steps have been run.
+ */
+function runAboutDialogUpdateTest(params, steps) {
+  let aboutDialog;
+  function processAboutDialogStep(step) {
+    if (typeof step == "function") {
+      return step(aboutDialog);
+    }
+
+    const {
+      panelId,
+      checkActiveUpdate,
+      continueFile,
+      downloadInfo,
+      forceApply,
+      noContinue,
+      expectedStateOverride,
+    } = step;
+    return (async function () {
+      await TestUtils.waitForCondition(
+        () =>
+          aboutDialog.gAppUpdater &&
+          aboutDialog.gAppUpdater.selectedPanel?.id == panelId,
+        "Waiting for the expected panel ID: " + panelId,
+        undefined,
+        200
+      ).catch(e => {
+        // Instead of throwing let the check below fail the test so the panel
+        // ID and the expected panel ID is printed in the log.
+        logTestInfo(e);
+      });
+      let { selectedPanel } = aboutDialog.gAppUpdater;
+      is(selectedPanel.id, panelId, "The panel ID should equal " + panelId);
+      ok(
+        BrowserTestUtils.is_visible(selectedPanel),
+        "The panel should be visible"
+      );
+
+      if (
+        panelId == "downloading" &&
+        gAUS.currentState == Ci.nsIApplicationUpdateService.STATE_IDLE
+      ) {
+        // Now that `AUS.downloadUpdate` is async, we start showing the
+        // downloading panel while `AUS.downloadUpdate` is still resolving.
+        // But the below checks assume that this resolution has already
+        // happened. So we need to wait for things to actually resolve.
+        debugDump("Waiting for downloading state to actually start");
+        await gAUS.stateTransition;
+
+        // Check that the checks that we made above are still valid.
+        selectedPanel = aboutDialog.gAppUpdater.selectedPanel;
+        is(selectedPanel.id, panelId, "The panel ID should equal " + panelId);
+        ok(
+          BrowserTestUtils.is_visible(selectedPanel),
+          "The panel should be visible"
+        );
+      }
+
+      let expectedState = Ci.nsIApplicationUpdateService.STATE_IDLE;
+      if (expectedStateOverride) {
+        expectedState = expectedStateOverride;
+      } else if (panelId == "apply") {
+        expectedState = Ci.nsIApplicationUpdateService.STATE_PENDING;
+      } else if (panelId == "downloading") {
+        expectedState = Ci.nsIApplicationUpdateService.STATE_DOWNLOADING;
+      } else if (panelId == "applying") {
+        expectedState = Ci.nsIApplicationUpdateService.STATE_STAGING;
+      }
+      let actualState = gAUS.currentState;
+      is(
+        actualState,
+        expectedState,
+        `The current update state should be ` +
+          `"${gAUS.getStateName(expectedState)}". Actual: ` +
+          `"${gAUS.getStateName(actualState)}"`
+      );
+
+      if (checkActiveUpdate) {
+        let activeUpdate =
+          checkActiveUpdate.state == STATE_DOWNLOADING
+            ? gUpdateManager.downloadingUpdate
+            : gUpdateManager.readyUpdate;
+        ok(!!activeUpdate, "There should be an active update");
+        is(
+          activeUpdate.state,
+          checkActiveUpdate.state,
+          "The active update state should equal " + checkActiveUpdate.state
+        );
+      } else {
+        ok(
+          !gUpdateManager.downloadingUpdate,
+          "There should not be a downloading update"
+        );
+        ok(!gUpdateManager.readyUpdate, "There should not be a ready update");
+      }
+
+      // Some tests just want to stop at the downloading state. These won't
+      // include a continue file in that state.
+      if (panelId == "downloading" && continueFile) {
+        for (let i = 0; i < downloadInfo.length; ++i) {
+          let data = downloadInfo[i];
+          await continueFileHandler(continueFile);
+          let patch = getPatchOfType(
+            data.patchType,
+            gUpdateManager.downloadingUpdate
+          );
+          // The update is removed early when the last download fails so check
+          // that there is a patch before proceeding.
+          let isLastPatch = i == downloadInfo.length - 1;
+          if (!isLastPatch || patch) {
+            let resultName = data.bitsResult ? "bitsResult" : "internalResult";
+            patch.QueryInterface(Ci.nsIWritablePropertyBag);
+            await TestUtils.waitForCondition(
+              () => patch.getProperty(resultName) == data[resultName],
+              "Waiting for expected patch property " +
+                resultName +
+                " value: " +
+                data[resultName],
+              undefined,
+              200
+            ).catch(e => {
+              // Instead of throwing let the check below fail the test so the
+              // property value and the expected property value is printed in
+              // the log.
+              logTestInfo(e);
+            });
+            is(
+              "" + patch.getProperty(resultName),
+              data[resultName],
+              "The patch property " +
+                resultName +
+                " value should equal " +
+                data[resultName]
+            );
+
+            // Check the download status text.  It should be something like,
+            // "1.4 of 1.4 KB".
+            let expectedText = DownloadUtils.getTransferTotal(
+              data[resultName] == gBadSizeResult ? 0 : patch.size,
+              patch.size
+            );
+            Assert.ok(
+              expectedText,
+              "Sanity check: Expected download status text should be non-empty"
+            );
+            if (aboutDialog.document.hasPendingL10nMutations) {
+              await BrowserTestUtils.waitForEvent(
+                aboutDialog.document,
+                "L10nMutationsFinished"
+              );
+            }
+            Assert.equal(
+              aboutDialog.document.querySelector(
+                `#downloading label[data-l10n-name="download-status"]`
+              ).textContent,
+              expectedText,
+              "Download status text should be correct"
+            );
+          }
+        }
+      } else if (continueFile) {
+        await continueFileHandler(continueFile);
+      }
+
+      let linkPanels = [
+        "downloadFailed",
+        "manualUpdate",
+        "unsupportedSystem",
+        "internalError",
+      ];
+      if (linkPanels.includes(panelId)) {
+        // The unsupportedSystem panel uses the update's detailsURL and the
+        // downloadFailed and manualUpdate panels use the app.update.url.manual
+        // preference.
+        let selector = "label.text-link";
+        if (selectedPanel.ownerDocument.hasPendingL10nMutations) {
+          await BrowserTestUtils.waitForEvent(
+            selectedPanel.ownerDocument,
+            "L10nMutationsFinished"
+          );
+        }
+        let link = selectedPanel.querySelector(selector);
+        is(
+          link.href,
+          gDetailsURL,
+          `The panel's link href should equal ${gDetailsURL}`
+        );
+        const assertNonEmptyText = (node, description) => {
+          let textContent = node.textContent.trim();
+          ok(textContent, `${description}, got "${textContent}"`);
+        };
+        assertNonEmptyText(
+          link,
+          `The panel's link should have non-empty textContent`
+        );
+        let linkWrapperClone = link.parentNode.cloneNode(true);
+        linkWrapperClone.querySelector(selector).remove();
+        assertNonEmptyText(
+          linkWrapperClone,
+          `The panel's link should have text around the link`
+        );
+      }
+
+      // Automatically click the download button unless `noContinue` was passed.
+      let buttonPanels = ["downloadAndInstall", "apply"];
+      if (buttonPanels.includes(panelId) && !noContinue) {
+        let buttonEl = selectedPanel.querySelector("button");
+        await TestUtils.waitForCondition(
+          () => aboutDialog.document.activeElement == buttonEl,
+          "The button should receive focus"
+        );
+        ok(!buttonEl.disabled, "The button should be enabled");
+        // Don't click the button on the apply panel since this will restart the
+        // application.
+        if (panelId != "apply" || forceApply) {
+          buttonEl.click();
+        }
+      }
+    })();
+  }
+
+  return (async function () {
+    Services.env.set("MOZ_TEST_SLOW_SKIP_UPDATE_STAGE", "1");
+    await SpecialPowers.pushPrefEnv({
+      set: [
+        [PREF_APP_UPDATE_DISABLEDFORTESTING, false],
+        [PREF_APP_UPDATE_URL_MANUAL, gDetailsURL],
+      ],
+    });
+
+    await setupTestUpdater();
+
+    let baseURL = URL_HTTP_UPDATE_SJS;
+    if (params.baseURL) {
+      baseURL = params.baseURL;
+    }
+    let queryString = params.queryString ? params.queryString : "";
+    let updateURL =
+      baseURL +
+      "?detailsURL=" +
+      gDetailsURL +
+      queryString +
+      getVersionParams(params.version);
+    if (params.backgroundUpdate) {
+      setUpdateURL(updateURL);
+      gAUS.checkForBackgroundUpdates();
+      if (params.continueFile) {
+        await continueFileHandler(params.continueFile);
+      }
+      if (params.waitForUpdateState) {
+        let whichUpdate =
+          params.waitForUpdateState == STATE_DOWNLOADING
+            ? "downloadingUpdate"
+            : "readyUpdate";
+        await TestUtils.waitForCondition(
+          () =>
+            gUpdateManager[whichUpdate] &&
+            gUpdateManager[whichUpdate].state == params.waitForUpdateState,
+          "Waiting for update state: " + params.waitForUpdateState,
+          undefined,
+          200
+        ).catch(e => {
+          // Instead of throwing let the check below fail the test so the panel
+          // ID and the expected panel ID is printed in the log.
+          logTestInfo(e);
+        });
+        // Display the UI after the update state equals the expected value.
+        is(
+          gUpdateManager[whichUpdate].state,
+          params.waitForUpdateState,
+          "The update state value should equal " + params.waitForUpdateState
+        );
+      }
+    } else {
+      updateURL += "&slowUpdateCheck=1&useSlowDownloadMar=1";
+      setUpdateURL(updateURL);
+    }
+
+    aboutDialog = await waitForAboutDialog();
+    registerCleanupFunction(() => {
+      aboutDialog.close();
+    });
+
+    for (let step of steps) {
+      await processAboutDialogStep(step);
+    }
+  })();
+}
+
+/**
+ * Runs an about:preferences update test. This will set various common prefs for
+ * updating and runs the provided list of steps.
+ *
+ * @param  params
+ *         An object containing parameters used to run the test.
+ * @param  steps
+ *         An array of test steps to perform. A step will either be an object
+ *         containing expected conditions and actions or a function to call.
+ * @return A promise which will resolve once all of the steps have been run.
+ */
+function runAboutPrefsUpdateTest(params, steps) {
+  let tab;
+  function processAboutPrefsStep(step) {
+    if (typeof step == "function") {
+      return step(tab);
+    }
+
+    const {
+      panelId,
+      checkActiveUpdate,
+      continueFile,
+      downloadInfo,
+      forceApply,
+      expectedStateOverride,
+    } = step;
+    return (async function () {
+      await SpecialPowers.spawn(
+        tab.linkedBrowser,
+        [{ panelId }],
+        async ({ panelId }) => {
+          await ContentTaskUtils.waitForCondition(
+            () => content.gAppUpdater.selectedPanel?.id == panelId,
+            "Waiting for the expected panel ID: " + panelId,
+            undefined,
+            200
+          ).catch(e => {
+            // Instead of throwing let the check below fail the test so the panel
+            // ID and the expected panel ID is printed in the log. Use info here
+            // instead of logTestInfo since logTestInfo isn't available in the
+            // content task.
+            info(e);
+          });
+          is(
+            content.gAppUpdater.selectedPanel.id,
+            panelId,
+            "The panel ID should equal " + panelId
+          );
+        }
+      );
+
+      if (
+        panelId == "downloading" &&
+        gAUS.currentState == Ci.nsIApplicationUpdateService.STATE_IDLE
+      ) {
+        // Now that `AUS.downloadUpdate` is async, we start showing the
+        // downloading panel while `AUS.downloadUpdate` is still resolving.
+        // But the below checks assume that this resolution has already
+        // happened. So we need to wait for things to actually resolve.
+        debugDump("Waiting for downloading state to actually start");
+        await gAUS.stateTransition;
+
+        // Check that the checks that we made above are still valid.
+        await SpecialPowers.spawn(
+          tab.linkedBrowser,
+          [{ panelId }],
+          ({ panelId }) => {
+            is(
+              content.gAppUpdater.selectedPanel.id,
+              panelId,
+              "The panel ID should equal " + panelId
+            );
+          }
+        );
+      }
+
+      let expectedState = Ci.nsIApplicationUpdateService.STATE_IDLE;
+      if (expectedStateOverride) {
+        expectedState = expectedStateOverride;
+      } else if (panelId == "apply") {
+        expectedState = Ci.nsIApplicationUpdateService.STATE_PENDING;
+      } else if (panelId == "downloading") {
+        expectedState = Ci.nsIApplicationUpdateService.STATE_DOWNLOADING;
+      } else if (panelId == "applying") {
+        expectedState = Ci.nsIApplicationUpdateService.STATE_STAGING;
+      }
+      let actualState = gAUS.currentState;
+      is(
+        actualState,
+        expectedState,
+        `The current update state should be ` +
+          `"${gAUS.getStateName(expectedState)}". Actual: ` +
+          `"${gAUS.getStateName(actualState)}"`
+      );
+
+      if (checkActiveUpdate) {
+        let activeUpdate =
+          checkActiveUpdate.state == STATE_DOWNLOADING
+            ? gUpdateManager.downloadingUpdate
+            : gUpdateManager.readyUpdate;
+        ok(!!activeUpdate, "There should be an active update");
+        is(
+          activeUpdate.state,
+          checkActiveUpdate.state,
+          "The active update state should equal " + checkActiveUpdate.state
+        );
+      } else {
+        ok(
+          !gUpdateManager.downloadingUpdate,
+          "There should not be a downloading update"
+        );
+        ok(!gUpdateManager.readyUpdate, "There should not be a ready update");
+      }
+
+      if (panelId == "downloading") {
+        if (!downloadInfo) {
+          logTestInfo("no downloadinfo, possible error?");
+        }
+        for (let i = 0; i < downloadInfo.length; ++i) {
+          let data = downloadInfo[i];
+          // The About Dialog tests always specify a continue file.
+          await continueFileHandler(continueFile);
+          let patch = getPatchOfType(
+            data.patchType,
+            gUpdateManager.downloadingUpdate
+          );
+          // The update is removed early when the last download fails so check
+          // that there is a patch before proceeding.
+          let isLastPatch = i == downloadInfo.length - 1;
+          if (!isLastPatch || patch) {
+            let resultName = data.bitsResult ? "bitsResult" : "internalResult";
+            patch.QueryInterface(Ci.nsIWritablePropertyBag);
+            await TestUtils.waitForCondition(
+              () => patch.getProperty(resultName) == data[resultName],
+              "Waiting for expected patch property " +
+                resultName +
+                " value: " +
+                data[resultName],
+              undefined,
+              200
+            ).catch(e => {
+              // Instead of throwing let the check below fail the test so the
+              // property value and the expected property value is printed in
+              // the log.
+              logTestInfo(e);
+            });
+            is(
+              "" + patch.getProperty(resultName),
+              data[resultName],
+              "The patch property " +
+                resultName +
+                " value should equal " +
+                data[resultName]
+            );
+
+            // Check the download status text.  It should be something like,
+            // "Downloading update — 1.4 of 1.4 KB".  We check only the second
+            // part to make sure that the downloaded size is updated correctly.
+            let actualText = await SpecialPowers.spawn(
+              tab.linkedBrowser,
+              [],
+              async () => {
+                const { document } = content;
+                if (document.hasPendingL10nMutations) {
+                  await ContentTaskUtils.waitForEvent(
+                    document,
+                    "L10nMutationsFinished"
+                  );
+                }
+                return document.getElementById("downloading").textContent;
+              }
+            );
+            let expectedSuffix = DownloadUtils.getTransferTotal(
+              data[resultName] == gBadSizeResult ? 0 : patch.size,
+              patch.size
+            );
+            Assert.ok(
+              expectedSuffix,
+              "Sanity check: Expected download status text should be non-empty"
+            );
+            Assert.ok(
+              actualText.endsWith(expectedSuffix),
+              "Download status text should end as expected: " +
+                JSON.stringify({ actualText, expectedSuffix })
+            );
+          }
+        }
+      } else if (continueFile) {
+        await continueFileHandler(continueFile);
+      }
+
+      await SpecialPowers.spawn(
+        tab.linkedBrowser,
+        [{ panelId, gDetailsURL, forceApply }],
+        async ({ panelId, gDetailsURL, forceApply }) => {
+          let linkPanels = [
+            "downloadFailed",
+            "manualUpdate",
+            "unsupportedSystem",
+            "internalError",
+          ];
+          if (linkPanels.includes(panelId)) {
+            let { selectedPanel } = content.gAppUpdater;
+            // The unsupportedSystem panel uses the update's detailsURL and the
+            // downloadFailed and manualUpdate panels use the app.update.url.manual
+            // preference.
+            let selector = "label.text-link";
+            // The downloadFailed panel in about:preferences uses an anchor
+            // instead of a label for the link.
+            if (selectedPanel.id == "downloadFailed") {
+              selector = "a.text-link";
+            }
+            // The manualUpdate panel in about:preferences uses
+            // the moz-support-link element which doesn't have
+            // the .text-link class.
+            if (selectedPanel.id == "manualUpdate") {
+              selector = "a.manualLink";
+            }
+            if (selectedPanel.ownerDocument.hasPendingL10nMutations) {
+              await ContentTaskUtils.waitForEvent(
+                selectedPanel.ownerDocument,
+                "L10nMutationsFinished"
+              );
+            }
+            let link = selectedPanel.querySelector(selector);
+            is(
+              link.href,
+              gDetailsURL,
+              `The panel's link href should equal ${gDetailsURL}`
+            );
+            const assertNonEmptyText = (node, description) => {
+              let textContent = node.textContent.trim();
+              ok(textContent, `${description}, got "${textContent}"`);
+            };
+            assertNonEmptyText(
+              link,
+              `The panel's link should have non-empty textContent`
+            );
+            let linkWrapperClone = link.parentNode.cloneNode(true);
+            linkWrapperClone.querySelector(selector).remove();
+            assertNonEmptyText(
+              linkWrapperClone,
+              `The panel's link should have text around the link`
+            );
+          }
+
+          let buttonPanels = ["downloadAndInstall", "apply"];
+          if (buttonPanels.includes(panelId)) {
+            let { selectedPanel } = content.gAppUpdater;
+            let buttonEl = selectedPanel.querySelector("button");
+            // Note: The about:preferences doesn't focus the button like the
+            // About Dialog does.
+            ok(!buttonEl.disabled, "The button should be enabled");
+            // Don't click the button on the apply panel since this will restart
+            // the application.
+            if (selectedPanel.id != "apply" || forceApply) {
+              buttonEl.click();
+            }
+          }
+        }
+      );
+    })();
+  }
+
+  return (async function () {
+    Services.env.set("MOZ_TEST_SLOW_SKIP_UPDATE_STAGE", "1");
+    await SpecialPowers.pushPrefEnv({
+      set: [
+        [PREF_APP_UPDATE_DISABLEDFORTESTING, false],
+        [PREF_APP_UPDATE_URL_MANUAL, gDetailsURL],
+      ],
+    });
+
+    await setupTestUpdater();
+
+    let baseURL = URL_HTTP_UPDATE_SJS;
+    if (params.baseURL) {
+      baseURL = params.baseURL;
+    }
+    let queryString = params.queryString ? params.queryString : "";
+    let updateURL =
+      baseURL +
+      "?detailsURL=" +
+      gDetailsURL +
+      queryString +
+      getVersionParams(params.version);
+    if (params.backgroundUpdate) {
+      setUpdateURL(updateURL);
+      gAUS.checkForBackgroundUpdates();
+      if (params.continueFile) {
+        await continueFileHandler(params.continueFile);
+      }
+      if (params.waitForUpdateState) {
+        // Wait until the update state equals the expected value before
+        // displaying the UI.
+        let whichUpdate =
+          params.waitForUpdateState == STATE_DOWNLOADING
+            ? "downloadingUpdate"
+            : "readyUpdate";
+        await TestUtils.waitForCondition(
+          () =>
+            gUpdateManager[whichUpdate] &&
+            gUpdateManager[whichUpdate].state == params.waitForUpdateState,
+          "Waiting for update state: " + params.waitForUpdateState,
+          undefined,
+          200
+        ).catch(e => {
+          // Instead of throwing let the check below fail the test so the panel
+          // ID and the expected panel ID is printed in the log.
+          logTestInfo(e);
+        });
+        is(
+          gUpdateManager[whichUpdate].state,
+          params.waitForUpdateState,
+          "The update state value should equal " + params.waitForUpdateState
+        );
+      }
+    } else {
+      updateURL += "&slowUpdateCheck=1&useSlowDownloadMar=1";
+      setUpdateURL(updateURL);
+    }
+
+    tab = await BrowserTestUtils.openNewForegroundTab(
+      gBrowser,
+      "about:preferences"
+    );
+    registerCleanupFunction(async () => {
+      await BrowserTestUtils.removeTab(tab);
+    });
+
+    // Scroll the UI into view so it is easier to troubleshoot tests.
+    await SpecialPowers.spawn(tab.linkedBrowser, [], async () => {
+      content.document.getElementById("updatesCategory").scrollIntoView();
+    });
+
+    for (let step of steps) {
+      await processAboutPrefsStep(step);
+    }
+  })();
+}
+
+/**
+ * Removes the modified update-settings.ini file so the updater will fail to
+ * stage an update.
+ */
+function removeUpdateSettingsIni() {
+  if (Services.prefs.getBoolPref(PREF_APP_UPDATE_STAGING_ENABLED)) {
+    let greDir = getGREDir();
+    let updateSettingsIniBak = greDir.clone();
+    updateSettingsIniBak.append(FILE_UPDATE_SETTINGS_INI_BAK);
+    if (updateSettingsIniBak.exists()) {
+      let updateSettingsIni = greDir.clone();
+      updateSettingsIni.append(FILE_UPDATE_SETTINGS_INI);
+      updateSettingsIni.remove(false);
+    }
+  }
+}
+
+/**
+ * Runs a telemetry update test. This will set various common prefs for
+ * updating, checks for an update, and waits for the specified observer
+ * notification.
+ *
+ * @param  updateParams
+ *         Params which will be sent to app_update.sjs.
+ * @param  event
+ *         The observer notification to wait for before proceeding.
+ * @param  stageFailure (optional)
+ *         Whether to force a staging failure by removing the modified
+ *         update-settings.ini file.
+ * @return A promise which will resolve after the .
+ */
+function runTelemetryUpdateTest(updateParams, event, stageFailure = false) {
+  return (async function () {
+    Services.telemetry.clearScalars();
+    Services.env.set("MOZ_TEST_SKIP_UPDATE_STAGE", "1");
+    await SpecialPowers.pushPrefEnv({
+      set: [[PREF_APP_UPDATE_DISABLEDFORTESTING, false]],
+    });
+
+    await setupTestUpdater();
+
+    if (stageFailure) {
+      removeUpdateSettingsIni();
+    }
+
+    let updateURL =
+      URL_HTTP_UPDATE_SJS +
+      "?detailsURL=" +
+      gDetailsURL +
+      updateParams +
+      getVersionParams();
+    setUpdateURL(updateURL);
+    gAUS.checkForBackgroundUpdates();
+    await waitForEvent(event);
+  })();
+}
diff --git a/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser.ini b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser.ini
new file mode 100644
index 0000000000..b5295f5eac
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser.ini
@@ -0,0 +1,18 @@
+[DEFAULT]
+head = head.js
+prefs =
+  app.update.BITS.enabled=false
+  browser.policies.alternatePath='<test-root>/toolkit/mozapps/update/tests/browser/manual_app_update_only/config_manual_app_update_only.json'
+support-files =
+  !/toolkit/mozapps/update/tests/browser/head.js
+  config_manual_app_update_only.json
+  ../../data/shared.js
+  ../../data/app_update.sjs
+  ../testConstants.js
+skip-if = os == 'win' && msix # Updater is disabled in MSIX builds
+
+[browser_aboutDialog_fc_autoUpdateFalse.js]
+[browser_aboutDialog_fc_autoUpdateTrue.js]
+[browser_aboutPrefs_fc_autoUpdateFalse.js]
+[browser_aboutPrefs_fc_autoUpdateTrue.js]
+[browser_noBackgroundUpdate.js]
diff --git a/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutDialog_fc_autoUpdateFalse.js b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutDialog_fc_autoUpdateFalse.js
new file mode 100644
index 0000000000..169e66033a
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutDialog_fc_autoUpdateFalse.js
@@ -0,0 +1,43 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_manual_app_update_policy() {
+  await setAppUpdateAutoEnabledHelper(false);
+
+  is(
+    Services.policies.isAllowed("autoAppUpdateChecking"),
+    false,
+    "autoAppUpdateChecking should be disabled by policy"
+  );
+  is(gAUS.manualUpdateOnly, true, "gAUS.manualUpdateOnly should be true");
+
+  let downloadInfo = [{ patchType: "partial", internalResult: "0" }];
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloadAndInstall",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutDialog_fc_autoUpdateTrue.js b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutDialog_fc_autoUpdateTrue.js
new file mode 100644
index 0000000000..0a59f59d71
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutDialog_fc_autoUpdateTrue.js
@@ -0,0 +1,43 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_manual_app_update_policy() {
+  await setAppUpdateAutoEnabledHelper(true);
+
+  is(
+    Services.policies.isAllowed("autoAppUpdateChecking"),
+    false,
+    "autoAppUpdateChecking should be disabled by policy"
+  );
+  is(gAUS.manualUpdateOnly, true, "gAUS.manualUpdateOnly should be true");
+
+  let downloadInfo = [{ patchType: "partial", internalResult: "0" }];
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutDialogUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloadAndInstall",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutPrefs_fc_autoUpdateFalse.js b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutPrefs_fc_autoUpdateFalse.js
new file mode 100644
index 0000000000..2d9608951e
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutPrefs_fc_autoUpdateFalse.js
@@ -0,0 +1,55 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_manual_app_update_policy() {
+  await setAppUpdateAutoEnabledHelper(false);
+
+  is(
+    Services.policies.isAllowed("autoAppUpdateChecking"),
+    false,
+    "autoAppUpdateChecking should be disabled by policy"
+  );
+  is(gAUS.manualUpdateOnly, true, "gAUS.manualUpdateOnly should be true");
+
+  let downloadInfo = [{ patchType: "partial", internalResult: "0" }];
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloadAndInstall",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+    async tab => {
+      await SpecialPowers.spawn(tab.linkedBrowser, [], async function () {
+        let setting = content.document.getElementById(
+          "updateSettingsContainer"
+        );
+        is(
+          setting.hidden,
+          true,
+          "Update choices should be disabled when manualUpdateOnly"
+        );
+      });
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutPrefs_fc_autoUpdateTrue.js b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutPrefs_fc_autoUpdateTrue.js
new file mode 100644
index 0000000000..b7b0c1027a
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_aboutPrefs_fc_autoUpdateTrue.js
@@ -0,0 +1,55 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_manual_app_update_policy() {
+  await setAppUpdateAutoEnabledHelper(true);
+
+  is(
+    Services.policies.isAllowed("autoAppUpdateChecking"),
+    false,
+    "autoAppUpdateChecking should be disabled by policy"
+  );
+  is(gAUS.manualUpdateOnly, true, "gAUS.manualUpdateOnly should be true");
+
+  let downloadInfo = [{ patchType: "partial", internalResult: "0" }];
+  // Since the partial should be successful specify an invalid size for the
+  // complete update.
+  let params = { queryString: "&invalidCompleteSize=1" };
+  await runAboutPrefsUpdateTest(params, [
+    {
+      panelId: "checkingForUpdates",
+      checkActiveUpdate: null,
+      continueFile: CONTINUE_CHECK,
+    },
+    {
+      panelId: "downloadAndInstall",
+      checkActiveUpdate: null,
+      continueFile: null,
+    },
+    {
+      panelId: "downloading",
+      checkActiveUpdate: { state: STATE_DOWNLOADING },
+      continueFile: CONTINUE_DOWNLOAD,
+      downloadInfo,
+    },
+    {
+      panelId: "apply",
+      checkActiveUpdate: { state: STATE_PENDING },
+      continueFile: null,
+    },
+    async tab => {
+      await SpecialPowers.spawn(tab.linkedBrowser, [], async function () {
+        let setting = content.document.getElementById(
+          "updateSettingsContainer"
+        );
+        is(
+          setting.hidden,
+          true,
+          "Update choices should be disabled when manualUpdateOnly"
+        );
+      });
+    },
+  ]);
+});
diff --git a/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_noBackgroundUpdate.js b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_noBackgroundUpdate.js
new file mode 100644
index 0000000000..38b27e31ad
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/manual_app_update_only/browser_noBackgroundUpdate.js
@@ -0,0 +1,17 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+add_task(async function test_manual_app_update_policy() {
+  // Unfortunately, we can't really test the other background update entry
+  // point, gAUS.notify, because it doesn't return anything and it would be
+  // a bit overkill to edit the nsITimerCallback interface just for this test.
+  // But the two entry points just immediately call the same function, so this
+  // should probably be alright.
+  is(
+    gAUS.checkForBackgroundUpdates(),
+    false,
+    "gAUS.checkForBackgroundUpdates() should not proceed with update check"
+  );
+});
diff --git a/toolkit/mozapps/update/tests/browser/manual_app_update_only/config_manual_app_update_only.json b/toolkit/mozapps/update/tests/browser/manual_app_update_only/config_manual_app_update_only.json
new file mode 100644
index 0000000000..4e7c785bc1
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/manual_app_update_only/config_manual_app_update_only.json
@@ -0,0 +1,5 @@
+{
+  "policies": {
+    "ManualAppUpdateOnly": true
+  }
+}
diff --git a/toolkit/mozapps/update/tests/browser/manual_app_update_only/head.js b/toolkit/mozapps/update/tests/browser/manual_app_update_only/head.js
new file mode 100644
index 0000000000..2a7576963b
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/manual_app_update_only/head.js
@@ -0,0 +1,9 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+Services.scriptloader.loadSubScript(
+  "chrome://mochitests/content/browser/toolkit/mozapps/update/tests/browser/head.js",
+  this
+);
diff --git a/toolkit/mozapps/update/tests/browser/testConstants.js b/toolkit/mozapps/update/tests/browser/testConstants.js
new file mode 100644
index 0000000000..915391054b
--- /dev/null
+++ b/toolkit/mozapps/update/tests/browser/testConstants.js
@@ -0,0 +1,7 @@
+const REL_PATH_DATA = "browser/toolkit/mozapps/update/tests/browser/";
+const URL_HOST = "http://127.0.0.1:8888";
+const URL_PATH_UPDATE_XML = "/" + REL_PATH_DATA + "app_update.sjs";
+const URL_HTTP_UPDATE_SJS = URL_HOST + URL_PATH_UPDATE_XML;
+const CONTINUE_CHECK = "continueCheck";
+const CONTINUE_DOWNLOAD = "continueDownload";
+const CONTINUE_STAGING = "continueStaging";