1 files changed, 667 insertions, 0 deletions
diff --git a/browser/components/firefoxview/firefox-view-tabs-setup-manager.sys.mjs b/browser/components/firefoxview/firefox-view-tabs-setup-manager.sys.mjs
new file mode 100644
index 0000000000..3696ae17b1
--- /dev/null
+++ b/browser/components/firefoxview/firefox-view-tabs-setup-manager.sys.mjs
@@ -0,0 +1,667 @@
+/* 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/. */
+
+/**
+ * This module exports the TabsSetupFlowManager singleton, which manages the state and
+ * diverse inputs which drive the Firefox View synced tabs setup flow
+ */
+
+import { PromiseUtils } from "resource://gre/modules/PromiseUtils.sys.mjs";
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  Log: "resource://gre/modules/Log.sys.mjs",
+  SyncedTabs: "resource://services-sync/SyncedTabs.sys.mjs",
+  SyncedTabsErrorHandler:
+    "resource:///modules/firefox-view-synced-tabs-error-handler.sys.mjs",
+  UIState: "resource://services-sync/UIState.sys.mjs",
+});
+
+XPCOMUtils.defineLazyGetter(lazy, "syncUtils", () => {
+  return ChromeUtils.importESModule("resource://services-sync/util.sys.mjs")
+    .Utils;
+});
+
+XPCOMUtils.defineLazyGetter(lazy, "fxAccounts", () => {
+  return ChromeUtils.importESModule(
+    "resource://gre/modules/FxAccounts.sys.mjs"
+  ).getFxAccountsSingleton();
+});
+
+const SYNC_TABS_PREF = "services.sync.engine.tabs";
+const TOPIC_TABS_CHANGED = "services.sync.tabs.changed";
+const MOBILE_PROMO_DISMISSED_PREF =
+  "browser.tabs.firefox-view.mobilePromo.dismissed";
+const LOGGING_PREF = "browser.tabs.firefox-view.logLevel";
+const TOPIC_SETUPSTATE_CHANGED = "firefox-view.setupstate.changed";
+const TOPIC_DEVICESTATE_CHANGED = "firefox-view.devicestate.changed";
+const TOPIC_DEVICELIST_UPDATED = "fxaccounts:devicelist_updated";
+const NETWORK_STATUS_CHANGED = "network:offline-status-changed";
+const SYNC_SERVICE_ERROR = "weave:service:sync:error";
+const FXA_DEVICE_CONNECTED = "fxaccounts:device_connected";
+const FXA_DEVICE_DISCONNECTED = "fxaccounts:device_disconnected";
+const SYNC_SERVICE_FINISHED = "weave:service:sync:finish";
+const PRIMARY_PASSWORD_UNLOCKED = "passwordmgr-crypto-login";
+const TAB_PICKUP_OPEN_STATE_PREF =
+  "browser.tabs.firefox-view.ui-state.tab-pickup.open";
+
+function openTabInWindow(window, url) {
+  const { switchToTabHavingURI } =
+    window.docShell.chromeEventHandler.ownerGlobal;
+  switchToTabHavingURI(url, true, {});
+}
+
+export const TabsSetupFlowManager = new (class {
+  constructor() {
+    this.QueryInterface = ChromeUtils.generateQI(["nsIObserver"]);
+
+    this.setupState = new Map();
+    this.resetInternalState();
+    this._currentSetupStateName = "";
+    this.syncIsConnected = lazy.UIState.get().syncEnabled;
+    this.didFxaTabOpen = false;
+
+    this.registerSetupState({
+      uiStateIndex: 0,
+      name: "error-state",
+      exitConditions: () => {
+        return lazy.SyncedTabsErrorHandler.isSyncReady();
+      },
+    });
+    this.registerSetupState({
+      uiStateIndex: 1,
+      name: "not-signed-in",
+      exitConditions: () => {
+        return this.fxaSignedIn;
+      },
+    });
+    this.registerSetupState({
+      uiStateIndex: 2,
+      name: "connect-secondary-device",
+      exitConditions: () => {
+        return this.secondaryDeviceConnected;
+      },
+    });
+    this.registerSetupState({
+      uiStateIndex: 3,
+      name: "disabled-tab-sync",
+      exitConditions: () => {
+        return this.syncTabsPrefEnabled;
+      },
+    });
+    this.registerSetupState({
+      uiStateIndex: 4,
+      name: "synced-tabs-loaded",
+      exitConditions: () => {
+        // This is the end state
+        return false;
+      },
+    });
+
+    Services.obs.addObserver(this, lazy.UIState.ON_UPDATE);
+    Services.obs.addObserver(this, TOPIC_DEVICELIST_UPDATED);
+    Services.obs.addObserver(this, NETWORK_STATUS_CHANGED);
+    Services.obs.addObserver(this, SYNC_SERVICE_ERROR);
+    Services.obs.addObserver(this, SYNC_SERVICE_FINISHED);
+    Services.obs.addObserver(this, TOPIC_TABS_CHANGED);
+    Services.obs.addObserver(this, PRIMARY_PASSWORD_UNLOCKED);
+    Services.obs.addObserver(this, FXA_DEVICE_CONNECTED);
+    Services.obs.addObserver(this, FXA_DEVICE_DISCONNECTED);
+
+    // this.syncTabsPrefEnabled will track the value of the tabs pref
+    XPCOMUtils.defineLazyPreferenceGetter(
+      this,
+      "syncTabsPrefEnabled",
+      SYNC_TABS_PREF,
+      false,
+      () => {
+        this.maybeUpdateUI(true);
+      }
+    );
+    XPCOMUtils.defineLazyPreferenceGetter(
+      this,
+      "mobilePromoDismissedPref",
+      MOBILE_PROMO_DISMISSED_PREF,
+      false,
+      () => {
+        this.maybeUpdateUI(true);
+      }
+    );
+
+    this._lastFxASignedIn = this.fxaSignedIn;
+    this.logger.debug(
+      "TabsSetupFlowManager constructor, fxaSignedIn:",
+      this._lastFxASignedIn
+    );
+    this.onSignedInChange();
+  }
+
+  resetInternalState() {
+    // assign initial values for all the managed internal properties
+    delete this._lastFxASignedIn;
+    this._currentSetupStateName = "not-signed-in";
+    this._shouldShowSuccessConfirmation = false;
+    this._didShowMobilePromo = false;
+    this.abortWaitingForTabs();
+
+    Services.obs.notifyObservers(null, TOPIC_DEVICESTATE_CHANGED);
+
+    // keep track of what is connected so we can respond to changes
+    this._deviceStateSnapshot = {
+      mobileDeviceConnected: this.mobileDeviceConnected,
+      secondaryDeviceConnected: this.secondaryDeviceConnected,
+    };
+    // keep track of tab-pickup-container instance visibilities
+    this._viewVisibilityStates = new Map();
+  }
+
+  get isPrimaryPasswordLocked() {
+    return lazy.syncUtils.mpLocked();
+  }
+
+  uninit() {
+    Services.obs.removeObserver(this, lazy.UIState.ON_UPDATE);
+    Services.obs.removeObserver(this, TOPIC_DEVICELIST_UPDATED);
+    Services.obs.removeObserver(this, NETWORK_STATUS_CHANGED);
+    Services.obs.removeObserver(this, SYNC_SERVICE_ERROR);
+    Services.obs.removeObserver(this, SYNC_SERVICE_FINISHED);
+    Services.obs.removeObserver(this, TOPIC_TABS_CHANGED);
+    Services.obs.removeObserver(this, PRIMARY_PASSWORD_UNLOCKED);
+    Services.obs.removeObserver(this, FXA_DEVICE_CONNECTED);
+    Services.obs.removeObserver(this, FXA_DEVICE_DISCONNECTED);
+  }
+  get hasVisibleViews() {
+    return Array.from(this._viewVisibilityStates.values()).reduce(
+      (hasVisible, visibility) => {
+        return hasVisible || visibility == "visible";
+      },
+      false
+    );
+  }
+  get currentSetupState() {
+    return this.setupState.get(this._currentSetupStateName);
+  }
+  get isTabSyncSetupComplete() {
+    return this.currentSetupState.uiStateIndex >= 4;
+  }
+  get uiStateIndex() {
+    return this.currentSetupState.uiStateIndex;
+  }
+  get fxaSignedIn() {
+    let { UIState } = lazy;
+    let syncState = UIState.get();
+    return (
+      UIState.isReady() &&
+      syncState.status === UIState.STATUS_SIGNED_IN &&
+      // syncEnabled just checks the "services.sync.username" pref has a value
+      syncState.syncEnabled
+    );
+  }
+  get secondaryDeviceConnected() {
+    if (!this.fxaSignedIn) {
+      return false;
+    }
+    let recentDevices = lazy.fxAccounts.device?.recentDeviceList?.length;
+    return recentDevices > 1;
+  }
+  get mobileDeviceConnected() {
+    if (!this.fxaSignedIn) {
+      return false;
+    }
+    let mobileClients = lazy.fxAccounts.device.recentDeviceList?.filter(
+      device => device.type == "mobile" || device.type == "tablet"
+    );
+    return mobileClients?.length > 0;
+  }
+  get shouldShowMobilePromo() {
+    return (
+      this.syncIsConnected &&
+      this.fxaSignedIn &&
+      this.currentSetupState.uiStateIndex >= 4 &&
+      !this.mobileDeviceConnected &&
+      !this.mobilePromoDismissedPref
+    );
+  }
+  get shouldShowMobileConnectedSuccess() {
+    return (
+      this.currentSetupState.uiStateIndex >= 3 &&
+      this._shouldShowSuccessConfirmation &&
+      this.mobileDeviceConnected
+    );
+  }
+  get logger() {
+    if (!this._log) {
+      let setupLog = lazy.Log.repository.getLogger("FirefoxView.TabsSetup");
+      setupLog.manageLevelFromPref(LOGGING_PREF);
+      setupLog.addAppender(
+        new lazy.Log.ConsoleAppender(new lazy.Log.BasicFormatter())
+      );
+      this._log = setupLog;
+    }
+    return this._log;
+  }
+
+  registerSetupState(state) {
+    this.setupState.set(state.name, state);
+  }
+
+  async observe(subject, topic, data) {
+    switch (topic) {
+      case lazy.UIState.ON_UPDATE:
+        this.logger.debug("Handling UIState update");
+        this.syncIsConnected = lazy.UIState.get().syncEnabled;
+        if (this._lastFxASignedIn !== this.fxaSignedIn) {
+          this.onSignedInChange();
+        } else {
+          await this.maybeUpdateUI();
+        }
+        this._lastFxASignedIn = this.fxaSignedIn;
+        break;
+      case TOPIC_DEVICELIST_UPDATED:
+        this.logger.debug("Handling observer notification:", topic, data);
+        const { deviceStateChanged, deviceAdded } = await this.refreshDevices();
+        if (deviceStateChanged) {
+          await this.maybeUpdateUI(true);
+        }
+        if (deviceAdded && this.secondaryDeviceConnected) {
+          this.logger.debug("device was added");
+          this._deviceAddedResultsNeverSeen = true;
+          if (this.hasVisibleViews) {
+            this.startWaitingForNewDeviceTabs();
+          }
+        }
+        break;
+      case FXA_DEVICE_CONNECTED:
+      case FXA_DEVICE_DISCONNECTED:
+        await lazy.fxAccounts.device.refreshDeviceList({ ignoreCached: true });
+        await this.maybeUpdateUI(true);
+        break;
+      case SYNC_SERVICE_ERROR:
+        this.logger.debug(`Handling ${SYNC_SERVICE_ERROR}`);
+        if (lazy.UIState.get().status == lazy.UIState.STATUS_SIGNED_IN) {
+          this.abortWaitingForTabs();
+          await this.maybeUpdateUI(true);
+        }
+        break;
+      case NETWORK_STATUS_CHANGED:
+        this.abortWaitingForTabs();
+        await this.maybeUpdateUI(true);
+        break;
+      case SYNC_SERVICE_FINISHED:
+        this.logger.debug(`Handling ${SYNC_SERVICE_FINISHED}`);
+        // We intentionally leave any empty-tabs timestamp
+        // as we may be still waiting for a sync that delivers some tabs
+        this._waitingForNextTabSync = false;
+        await this.maybeUpdateUI(true);
+        break;
+      case TOPIC_TABS_CHANGED:
+        this.stopWaitingForTabs();
+        break;
+      case PRIMARY_PASSWORD_UNLOCKED:
+        this.logger.debug(`Handling ${PRIMARY_PASSWORD_UNLOCKED}`);
+        this.tryToClearError();
+        break;
+    }
+  }
+
+  updateViewVisibility(instanceId, visibility) {
+    const wasVisible = this.hasVisibleViews;
+    this.logger.debug(
+      `updateViewVisibility for instance: ${instanceId}, visibility: ${visibility}`
+    );
+    if (visibility == "unloaded") {
+      this._viewVisibilityStates.delete(instanceId);
+    } else {
+      this._viewVisibilityStates.set(instanceId, visibility);
+    }
+    const isVisible = this.hasVisibleViews;
+    if (isVisible && !wasVisible) {
+      // If we're already timing waiting for tabs from a newly-added device
+      // we might be able to stop
+      if (this._noTabsVisibleFromAddedDeviceTimestamp) {
+        return this.stopWaitingForNewDeviceTabs();
+      }
+      if (this._deviceAddedResultsNeverSeen) {
+        // If this is the first time a view has been visible since a device was added
+        // we may want to start the empty-tabs visible timer
+        return this.startWaitingForNewDeviceTabs();
+      }
+    }
+    if (!isVisible) {
+      this.logger.debug(
+        "Resetting timestamp and tabs pending flags as there are no visible views"
+      );
+      // if there's no view visible, we're not really waiting anymore
+      this.abortWaitingForTabs();
+    }
+    return null;
+  }
+
+  get waitingForTabs() {
+    return (
+      // signed in & at least 1 other device is syncing indicates there's something to wait for
+      this.secondaryDeviceConnected && this._waitingForNextTabSync
+    );
+  }
+
+  abortWaitingForTabs() {
+    this._waitingForNextTabSync = false;
+    // also clear out the device-added / tabs pending flags
+    this._noTabsVisibleFromAddedDeviceTimestamp = 0;
+    this._deviceAddedResultsNeverSeen = false;
+  }
+
+  startWaitingForTabs() {
+    if (!this._waitingForNextTabSync) {
+      this._waitingForNextTabSync = true;
+      Services.obs.notifyObservers(null, TOPIC_SETUPSTATE_CHANGED);
+    }
+  }
+
+  async stopWaitingForTabs() {
+    const wasWaiting = this.waitingForTabs;
+    if (this.hasVisibleViews && this._deviceAddedResultsNeverSeen) {
+      await this.stopWaitingForNewDeviceTabs();
+    }
+    this._waitingForNextTabSync = false;
+    if (wasWaiting) {
+      Services.obs.notifyObservers(null, TOPIC_SETUPSTATE_CHANGED);
+    }
+  }
+
+  async onSignedInChange() {
+    this.logger.debug("onSignedInChange, fxaSignedIn:", this.fxaSignedIn);
+    // update UI to make the state change
+    await this.maybeUpdateUI(true);
+    if (!this.fxaSignedIn) {
+      // As we just signed out, ensure the waiting flag is reset for next time around
+      this.abortWaitingForTabs();
+      return;
+    }
+
+    // Set Tab pickup open state pref to true when signing in
+    Services.prefs.setBoolPref(TAB_PICKUP_OPEN_STATE_PREF, true);
+
+    // Now we need to figure out if we have recently synced tabs to show
+    // Or, if we are going to need to trigger a tab sync for them
+    const recentTabs = await lazy.SyncedTabs.getRecentTabs(50);
+
+    if (!this.fxaSignedIn) {
+      // We got signed-out in the meantime. We should get an ON_UPDATE which will put us
+      // back in the right state, so we just do nothing here
+      return;
+    }
+
+    // When SyncedTabs has resolved the getRecentTabs promise,
+    // we also know we can update devices-related internal state
+    const { deviceStateChanged } = await this.refreshDevices();
+    if (deviceStateChanged) {
+      this.logger.debug(
+        "onSignedInChange, after refreshDevices, calling maybeUpdateUI"
+      );
+      // give the UI an opportunity to update as secondaryDeviceConnected or
+      // mobileDeviceConnected have changed value
+      await this.maybeUpdateUI(true);
+    }
+
+    // If we can't get recent tabs, we need to trigger a request for them
+    const tabSyncNeeded = !recentTabs?.length;
+    this.logger.debug("onSignedInChange, tabSyncNeeded:", tabSyncNeeded);
+
+    if (tabSyncNeeded) {
+      this.startWaitingForTabs();
+      this.logger.debug(
+        "isPrimaryPasswordLocked:",
+        this.isPrimaryPasswordLocked
+      );
+      this.logger.debug("onSignedInChange, no recentTabs, calling syncTabs");
+      // If the syncTabs call rejects or resolves false we need to clear the waiting
+      // flag and update UI
+      this.syncTabs()
+        .catch(ex => {
+          this.logger.debug("onSignedInChange, syncTabs rejected:", ex);
+          this.stopWaitingForTabs();
+        })
+        .then(willSync => {
+          if (!willSync) {
+            this.logger.debug("onSignedInChange, no tab sync expected");
+            this.stopWaitingForTabs();
+          }
+        });
+    }
+  }
+
+  async startWaitingForNewDeviceTabs() {
+    // if we're already waiting for tabs, don't reset
+    if (this._noTabsVisibleFromAddedDeviceTimestamp) {
+      return;
+    }
+
+    // take a timestamp whenever the latest device is added and we have 0 tabs to show,
+    // allowing us to track how long we show an empty list after a new device is added
+    const hasRecentTabs = (await lazy.SyncedTabs.getRecentTabs(1)).length;
+    if (this.hasVisibleViews && !hasRecentTabs) {
+      this._noTabsVisibleFromAddedDeviceTimestamp = Date.now();
+      this.logger.debug(
+        "New device added with 0 synced tabs to show, storing timestamp:",
+        this._noTabsVisibleFromAddedDeviceTimestamp
+      );
+    }
+  }
+
+  async stopWaitingForNewDeviceTabs() {
+    if (!this._noTabsVisibleFromAddedDeviceTimestamp) {
+      return;
+    }
+    const recentTabs = await lazy.SyncedTabs.getRecentTabs(1);
+    if (recentTabs.length) {
+      // We have been waiting for > 0 tabs after a newly-added device, record
+      // the time elapsed
+      const elapsed = Date.now() - this._noTabsVisibleFromAddedDeviceTimestamp;
+      this.logger.debug(
+        "stopWaitingForTabs, resetting _noTabsVisibleFromAddedDeviceTimestamp and recording telemetry:",
+        Math.round(elapsed / 1000)
+      );
+      this._noTabsVisibleFromAddedDeviceTimestamp = 0;
+      this._deviceAddedResultsNeverSeen = false;
+      Services.telemetry.recordEvent(
+        "firefoxview",
+        "synced_tabs_empty",
+        "since_device_added",
+        Math.round(elapsed / 1000).toString()
+      );
+    } else {
+      // we are still waiting for some tabs to show...
+      this.logger.debug(
+        "stopWaitingForTabs: Still no recent tabs, we are still waiting"
+      );
+    }
+  }
+
+  async refreshDevices() {
+    // If current device not found in recent device list, refresh device list
+    if (
+      !lazy.fxAccounts.device.recentDeviceList?.some(
+        device => device.isCurrentDevice
+      )
+    ) {
+      await lazy.fxAccounts.device.refreshDeviceList({ ignoreCached: true });
+    }
+
+    // compare new values to the previous values
+    const mobileDeviceConnected = this.mobileDeviceConnected;
+    const secondaryDeviceConnected = this.secondaryDeviceConnected;
+    const oldDevicesCount = this._deviceStateSnapshot?.devicesCount ?? 0;
+    const devicesCount = lazy.fxAccounts.device?.recentDeviceList?.length ?? 0;
+
+    this.logger.debug(
+      `refreshDevices, mobileDeviceConnected: ${mobileDeviceConnected}, `,
+      `secondaryDeviceConnected: ${secondaryDeviceConnected}`
+    );
+
+    let deviceStateChanged =
+      this._deviceStateSnapshot.mobileDeviceConnected !=
+        mobileDeviceConnected ||
+      this._deviceStateSnapshot.secondaryDeviceConnected !=
+        secondaryDeviceConnected;
+    if (
+      mobileDeviceConnected &&
+      !this._deviceStateSnapshot.mobileDeviceConnected
+    ) {
+      // a mobile device was added, show success if we previously showed the promo
+      this._shouldShowSuccessConfirmation = this._didShowMobilePromo;
+    } else if (
+      !mobileDeviceConnected &&
+      this._deviceStateSnapshot.mobileDeviceConnected
+    ) {
+      // no mobile device connected now, reset
+      Services.prefs.clearUserPref(MOBILE_PROMO_DISMISSED_PREF);
+      this._shouldShowSuccessConfirmation = false;
+    }
+    this._deviceStateSnapshot = {
+      mobileDeviceConnected,
+      secondaryDeviceConnected,
+      devicesCount,
+    };
+    if (deviceStateChanged) {
+      this.logger.debug("refreshDevices: device state did change");
+      if (!secondaryDeviceConnected) {
+        this.logger.debug(
+          "We lost a device, now claim sync hasn't worked before."
+        );
+        Services.obs.notifyObservers(null, TOPIC_DEVICESTATE_CHANGED);
+      }
+    } else {
+      this.logger.debug("refreshDevices: no device state change");
+    }
+    return {
+      deviceStateChanged,
+      deviceAdded: oldDevicesCount < devicesCount,
+    };
+  }
+
+  async maybeUpdateUI(forceUpdate = false) {
+    let nextSetupStateName = this._currentSetupStateName;
+    let errorState = null;
+    let stateChanged = false;
+
+    // state transition conditions
+    for (let state of this.setupState.values()) {
+      nextSetupStateName = state.name;
+      if (!state.exitConditions()) {
+        this.logger.debug(
+          "maybeUpdateUI, conditions not met to exit state: ",
+          nextSetupStateName
+        );
+        break;
+      }
+    }
+
+    let setupState = this.currentSetupState;
+    const state = this.setupState.get(nextSetupStateName);
+    const uiStateIndex = state.uiStateIndex;
+
+    if (
+      uiStateIndex == 0 ||
+      nextSetupStateName != this._currentSetupStateName
+    ) {
+      setupState = state;
+      this._currentSetupStateName = nextSetupStateName;
+      stateChanged = true;
+    }
+    this.logger.debug(
+      "maybeUpdateUI, will notify update?:",
+      stateChanged,
+      forceUpdate
+    );
+    if (stateChanged || forceUpdate) {
+      if (this.shouldShowMobilePromo) {
+        this._didShowMobilePromo = true;
+      }
+      if (uiStateIndex == 0) {
+        // Use idleDispatch() to give observers a chance to resolve before
+        // determining the new state.
+        errorState = await PromiseUtils.idleDispatch(() =>
+          lazy.SyncedTabsErrorHandler.getErrorType()
+        );
+        this.logger.debug("maybeUpdateUI, in error state:", errorState);
+      }
+      Services.obs.notifyObservers(null, TOPIC_SETUPSTATE_CHANGED, errorState);
+    }
+    if ("function" == typeof setupState.enter) {
+      setupState.enter();
+    }
+  }
+
+  dismissMobilePromo() {
+    Services.prefs.setBoolPref(MOBILE_PROMO_DISMISSED_PREF, true);
+  }
+
+  dismissMobileConfirmation() {
+    this._shouldShowSuccessConfirmation = false;
+    this._didShowMobilePromo = false;
+    this.maybeUpdateUI(true);
+  }
+
+  async openFxASignup(window) {
+    if (!(await lazy.fxAccounts.constructor.canConnectAccount())) {
+      return;
+    }
+    const url =
+      await lazy.fxAccounts.constructor.config.promiseConnectAccountURI(
+        "fx-view"
+      );
+    this.didFxaTabOpen = true;
+    openTabInWindow(window, url, true);
+    Services.telemetry.recordEvent("firefoxview", "fxa_continue", "sync", null);
+  }
+
+  async openFxAPairDevice(window) {
+    const url = await lazy.fxAccounts.constructor.config.promisePairingURI({
+      entrypoint: "fx-view",
+    });
+    this.didFxaTabOpen = true;
+    openTabInWindow(window, url, true);
+    Services.telemetry.recordEvent("firefoxview", "fxa_mobile", "sync", null, {
+      has_devices: this.secondaryDeviceConnected.toString(),
+    });
+  }
+
+  syncOpenTabs(containerElem) {
+    // Flip the pref on.
+    // The observer should trigger re-evaluating state and advance to next step
+    Services.prefs.setBoolPref(SYNC_TABS_PREF, true);
+  }
+
+  async syncOnPageReload() {
+    if (lazy.UIState.isReady() && this.fxaSignedIn) {
+      this.startWaitingForTabs();
+      await this.syncTabs(true);
+    }
+  }
+
+  tryToClearError() {
+    if (lazy.UIState.isReady() && this.fxaSignedIn) {
+      this.startWaitingForTabs();
+      if (this.isPrimaryPasswordLocked) {
+        lazy.syncUtils.ensureMPUnlocked();
+      }
+      this.logger.debug("tryToClearError: triggering new tab sync");
+      this.syncTabs();
+      Services.tm.dispatchToMainThread(() => {});
+    } else {
+      this.logger.debug(
+        `tryToClearError: unable to sync, isReady: ${lazy.UIState.isReady()}, fxaSignedIn: ${
+          this.fxaSignedIn
+        }`
+      );
+    }
+  }
+  // For easy overriding in tests
+  syncTabs(force = false) {
+    return lazy.SyncedTabs.syncTabs(force);
+  }
+})();