Adding upstream version 124.0.1.upstream/124.0.1

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

1 files changed, 887 insertions, 0 deletions

diff --git a/toolkit/modules/Region.sys.mjs b/toolkit/modules/Region.sys.mjs
new file mode 100644
index 0000000000..a07e73f378
--- /dev/null
+++ b/toolkit/modules/Region.sys.mjs
@@ -0,0 +1,887 @@
+/* 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/. */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+
+import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
+
+import { RemoteSettings } from "resource://services-settings/remote-settings.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  LocationHelper: "resource://gre/modules/LocationHelper.sys.mjs",
+  setTimeout: "resource://gre/modules/Timer.sys.mjs",
+});
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "wifiScanningEnabled",
+  "browser.region.network.scan",
+  true
+);
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "networkTimeout",
+  "browser.region.timeout",
+  5000
+);
+
+// Retry the region lookup every hour on failure, a failure
+// is likely to be a service failure so this gives the
+// service some time to restore. Setting to 0 disabled retries.
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "retryTimeout",
+  "browser.region.retry-timeout",
+  60 * 60 * 1000
+);
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "loggingEnabled",
+  "browser.region.log",
+  false
+);
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "cacheBustEnabled",
+  "browser.region.update.enabled",
+  false
+);
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "updateDebounce",
+  "browser.region.update.debounce",
+  60 * 60 * 24
+);
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "lastUpdated",
+  "browser.region.update.updated",
+  0
+);
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  lazy,
+  "localGeocodingEnabled",
+  "browser.region.local-geocoding",
+  false
+);
+
+XPCOMUtils.defineLazyServiceGetter(
+  lazy,
+  "timerManager",
+  "@mozilla.org/updates/timer-manager;1",
+  "nsIUpdateTimerManager"
+);
+
+const log = console.createInstance({
+  prefix: "Region.sys.mjs",
+  maxLogLevel: lazy.loggingEnabled ? "All" : "Warn",
+});
+
+const REGION_PREF = "browser.search.region";
+const COLLECTION_ID = "regions";
+const GEOLOCATION_TOPIC = "geolocation-position-events";
+
+// Prefix for all the region updating related preferences.
+const UPDATE_PREFIX = "browser.region.update";
+
+// The amount of time (in seconds) we need to be in a new
+// location before we update the home region.
+// Currently set to 2 weeks.
+const UPDATE_INTERVAL = 60 * 60 * 24 * 14;
+
+const MAX_RETRIES = 3;
+
+// If the user never uses geolocation, schedule a periodic
+// update to check the current location (in seconds).
+const UPDATE_CHECK_NAME = "region-update-timer";
+const UPDATE_CHECK_INTERVAL = 60 * 60 * 24 * 7;
+
+// Let child processes read the current home value
+// but dont trigger redundant updates in them.
+let inChildProcess =
+  Services.appinfo.processType != Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT;
+
+/**
+ * This module keeps track of the users current region (country).
+ * so the SearchService and other consumers can apply region
+ * specific customisations.
+ */
+class RegionDetector {
+  // The users home location.
+  _home = null;
+  // The most recent location the user was detected.
+  _current = null;
+  // The RemoteSettings client used to sync region files.
+  _rsClient = null;
+  // Keep track of the wifi data across listener events.
+  _wifiDataPromise = null;
+  // Keep track of how many times we have tried to fetch
+  // the users region during failure.
+  _retryCount = 0;
+  // Let tests wait for init to complete.
+  _initPromise = null;
+  // Topic for Observer events fired by Region.sys.mjs.
+  REGION_TOPIC = "browser-region-updated";
+  // Values for telemetry.
+  TELEMETRY = {
+    SUCCESS: 0,
+    NO_RESULT: 1,
+    TIMEOUT: 2,
+    ERROR: 3,
+  };
+
+  /**
+   * Read currently stored region data and if needed trigger background
+   * region detection.
+   */
+  async init() {
+    if (this._initPromise) {
+      return this._initPromise;
+    }
+    if (lazy.cacheBustEnabled && !inChildProcess) {
+      Services.tm.idleDispatchToMainThread(() => {
+        lazy.timerManager.registerTimer(
+          UPDATE_CHECK_NAME,
+          () => this._updateTimer(),
+          UPDATE_CHECK_INTERVAL
+        );
+      });
+    }
+    let promises = [];
+    this._home = Services.prefs.getCharPref(REGION_PREF, null);
+    if (!this._home && !inChildProcess) {
+      promises.push(this._idleDispatch(() => this._fetchRegion()));
+    }
+    if (lazy.localGeocodingEnabled && !inChildProcess) {
+      promises.push(this._idleDispatch(() => this._setupRemoteSettings()));
+    }
+    return (this._initPromise = Promise.all(promises));
+  }
+
+  /**
+   * Get the region we currently consider the users home.
+   *
+   * @returns {string}
+   *   The users current home region.
+   */
+  get home() {
+    return this._home;
+  }
+
+  /**
+   * Get the last region we detected the user to be in.
+   *
+   * @returns {string}
+   *   The users current region.
+   */
+  get current() {
+    return this._current;
+  }
+
+  /**
+   * Fetch the users current region.
+   *
+   * @returns {string}
+   *   The country_code defining users current region.
+   */
+  async _fetchRegion() {
+    if (this._retryCount >= MAX_RETRIES) {
+      return null;
+    }
+    let startTime = Date.now();
+    let telemetryResult = this.TELEMETRY.SUCCESS;
+    let result = null;
+
+    try {
+      result = await this._getRegion();
+    } catch (err) {
+      telemetryResult = this.TELEMETRY[err.message] || this.TELEMETRY.ERROR;
+      log.error("Failed to fetch region", err);
+      if (lazy.retryTimeout) {
+        this._retryCount++;
+        lazy.setTimeout(() => {
+          Services.tm.idleDispatchToMainThread(this._fetchRegion.bind(this));
+        }, lazy.retryTimeout);
+      }
+    }
+
+    let took = Date.now() - startTime;
+    if (result) {
+      await this._storeRegion(result);
+    }
+    Services.telemetry
+      .getHistogramById("SEARCH_SERVICE_COUNTRY_FETCH_TIME_MS")
+      .add(took);
+
+    Services.telemetry
+      .getHistogramById("SEARCH_SERVICE_COUNTRY_FETCH_RESULT")
+      .add(telemetryResult);
+
+    return result;
+  }
+
+  /**
+   * Validate then store the region and report telemetry.
+   *
+   * @param region
+   *   The region to store.
+   */
+  async _storeRegion(region) {
+    let prefix = "SEARCH_SERVICE";
+    let isTimezoneUS = isUSTimezone();
+    // If it's a US region, but not a US timezone, we don't store
+    // the value. This works because no region defaults to
+    // ZZ (unknown) in nsURLFormatter
+    if (region != "US" || isTimezoneUS) {
+      this._setCurrentRegion(region, true);
+    }
+
+    // and telemetry...
+    if (region == "US" && !isTimezoneUS) {
+      log.info("storeRegion mismatch - US Region, non-US timezone");
+      Services.telemetry
+        .getHistogramById(`${prefix}_US_COUNTRY_MISMATCHED_TIMEZONE`)
+        .add(1);
+    }
+    if (region != "US" && isTimezoneUS) {
+      log.info("storeRegion mismatch - non-US Region, US timezone");
+      Services.telemetry
+        .getHistogramById(`${prefix}_US_TIMEZONE_MISMATCHED_COUNTRY`)
+        .add(1);
+    }
+    // telemetry to compare our geoip response with
+    // platform-specific country data.
+    // On Mac and Windows, we can get a country code via sysinfo
+    let platformCC = await Services.sysinfo.countryCode;
+    if (platformCC) {
+      let probeUSMismatched, probeNonUSMismatched;
+      switch (AppConstants.platform) {
+        case "macosx":
+          probeUSMismatched = `${prefix}_US_COUNTRY_MISMATCHED_PLATFORM_OSX`;
+          probeNonUSMismatched = `${prefix}_NONUS_COUNTRY_MISMATCHED_PLATFORM_OSX`;
+          break;
+        case "win":
+          probeUSMismatched = `${prefix}_US_COUNTRY_MISMATCHED_PLATFORM_WIN`;
+          probeNonUSMismatched = `${prefix}_NONUS_COUNTRY_MISMATCHED_PLATFORM_WIN`;
+          break;
+        default:
+          log.error(
+            "Platform " +
+              Services.appinfo.OS +
+              " has system country code but no search service telemetry probes"
+          );
+          break;
+      }
+      if (probeUSMismatched && probeNonUSMismatched) {
+        if (region == "US" || platformCC == "US") {
+          // one of the 2 said US, so record if they are the same.
+          Services.telemetry
+            .getHistogramById(probeUSMismatched)
+            .add(region != platformCC);
+        } else {
+          // non-US - record if they are the same
+          Services.telemetry
+            .getHistogramById(probeNonUSMismatched)
+            .add(region != platformCC);
+        }
+      }
+    }
+  }
+
+  /**
+   * Save the update current region and check if the home region
+   * also needs an update.
+   *
+   * @param {string} region
+   *   The region to store.
+   */
+  _setCurrentRegion(region = "") {
+    log.info("Setting current region:", region);
+    this._current = region;
+
+    let now = Math.round(Date.now() / 1000);
+    let prefs = Services.prefs;
+    prefs.setIntPref(`${UPDATE_PREFIX}.updated`, now);
+
+    // Interval is in seconds.
+    let interval = prefs.getIntPref(
+      `${UPDATE_PREFIX}.interval`,
+      UPDATE_INTERVAL
+    );
+    let seenRegion = prefs.getCharPref(`${UPDATE_PREFIX}.region`, null);
+    let firstSeen = prefs.getIntPref(`${UPDATE_PREFIX}.first-seen`, 0);
+
+    // If we don't have a value for .home we can set it immediately.
+    if (!this._home) {
+      this._setHomeRegion(region);
+    } else if (region != this._home && region != seenRegion) {
+      // If we are in a different region than what is currently
+      // considered home, then keep track of when we first
+      // seen the new location.
+      prefs.setCharPref(`${UPDATE_PREFIX}.region`, region);
+      prefs.setIntPref(`${UPDATE_PREFIX}.first-seen`, now);
+    } else if (region != this._home && region == seenRegion) {
+      // If we have been in the new region for longer than
+      // a specified time period, then set that as the new home.
+      if (now >= firstSeen + interval) {
+        this._setHomeRegion(region);
+      }
+    } else {
+      // If we are at home again, stop tracking the seen region.
+      prefs.clearUserPref(`${UPDATE_PREFIX}.region`);
+      prefs.clearUserPref(`${UPDATE_PREFIX}.first-seen`);
+    }
+  }
+
+  // Wrap a string as a nsISupports.
+  _createSupportsString(data) {
+    let string = Cc["@mozilla.org/supports-string;1"].createInstance(
+      Ci.nsISupportsString
+    );
+    string.data = data;
+    return string;
+  }
+
+  /**
+   * Save the updated home region and notify observers.
+   *
+   * @param {string} region
+   *   The region to store.
+   * @param {boolean} [notify]
+   *   Tests can disable the notification for convenience as it
+   *   may trigger an engines reload.
+   */
+  _setHomeRegion(region, notify = true) {
+    if (region == this._home) {
+      return;
+    }
+    log.info("Updating home region:", region);
+    this._home = region;
+    Services.prefs.setCharPref("browser.search.region", region);
+    if (notify) {
+      Services.obs.notifyObservers(
+        this._createSupportsString(region),
+        this.REGION_TOPIC
+      );
+    }
+  }
+
+  /**
+   * Make the request to fetch the region from the configured service.
+   */
+  async _getRegion() {
+    log.info("_getRegion called");
+    let fetchOpts = {
+      headers: { "Content-Type": "application/json" },
+      credentials: "omit",
+    };
+    if (lazy.wifiScanningEnabled) {
+      let wifiData = await this._fetchWifiData();
+      if (wifiData) {
+        let postData = JSON.stringify({ wifiAccessPoints: wifiData });
+        log.info("Sending wifi details: ", wifiData);
+        fetchOpts.method = "POST";
+        fetchOpts.body = postData;
+      }
+    }
+    let url = Services.urlFormatter.formatURLPref("browser.region.network.url");
+    log.info("_getRegion url is: ", url);
+
+    if (!url) {
+      return null;
+    }
+
+    try {
+      let req = await this._fetchTimeout(url, fetchOpts, lazy.networkTimeout);
+      let res = await req.json();
+      log.info("_getRegion returning ", res.country_code);
+      return res.country_code;
+    } catch (err) {
+      log.error("Error fetching region", err);
+      let errCode = err.message in this.TELEMETRY ? err.message : "NO_RESULT";
+      throw new Error(errCode);
+    }
+  }
+
+  /**
+   * Setup the RemoteSetting client + sync listener and ensure
+   * the map files are downloaded.
+   */
+  async _setupRemoteSettings() {
+    log.info("_setupRemoteSettings");
+    this._rsClient = RemoteSettings(COLLECTION_ID);
+    this._rsClient.on("sync", this._onRegionFilesSync.bind(this));
+    await this._ensureRegionFilesDownloaded();
+    // Start listening to geolocation events only after
+    // we know the maps are downloded.
+    Services.obs.addObserver(this, GEOLOCATION_TOPIC);
+  }
+
+  /**
+   * Called when RemoteSettings syncs new data, clean up any
+   * stale attachments and download any new ones.
+   *
+   * @param {Object} syncData
+   *   Object describing the data that has just been synced.
+   */
+  async _onRegionFilesSync({ data: { deleted } }) {
+    log.info("_onRegionFilesSync");
+    const toDelete = deleted.filter(d => d.attachment);
+    // Remove local files of deleted records
+    await Promise.all(
+      toDelete.map(entry => this._rsClient.attachments.deleteDownloaded(entry))
+    );
+    await this._ensureRegionFilesDownloaded();
+  }
+
+  /**
+   * Download the RemoteSetting record attachments, when they are
+   * successfully downloaded set a flag so we can start using them
+   * for geocoding.
+   */
+  async _ensureRegionFilesDownloaded() {
+    log.info("_ensureRegionFilesDownloaded");
+    let records = (await this._rsClient.get()).filter(d => d.attachment);
+    log.info("_ensureRegionFilesDownloaded", records);
+    if (!records.length) {
+      log.info("_ensureRegionFilesDownloaded: Nothing to download");
+      return;
+    }
+    await Promise.all(records.map(r => this._rsClient.attachments.download(r)));
+    log.info("_ensureRegionFilesDownloaded complete");
+    this._regionFilesReady = true;
+  }
+
+  /**
+   * Fetch an attachment from RemoteSettings.
+   *
+   * @param {String} id
+   *   The id of the record to fetch the attachment from.
+   */
+  async _fetchAttachment(id) {
+    let record = (await this._rsClient.get({ filters: { id } })).pop();
+    let { buffer } = await this._rsClient.attachments.download(record);
+    let text = new TextDecoder("utf-8").decode(buffer);
+    return JSON.parse(text);
+  }
+
+  /**
+   * Get a map of the world with region definitions.
+   */
+  async _getPlainMap() {
+    return this._fetchAttachment("world");
+  }
+
+  /**
+   * Get a map with the regions expanded by a few km to help
+   * fallback lookups when a location is not within a region.
+   */
+  async _getBufferedMap() {
+    return this._fetchAttachment("world-buffered");
+  }
+
+  /**
+   * Gets the users current location using the same reverse IP
+   * request that is used for GeoLocation requests.
+   *
+   * @returns {Object} location
+   *   Object representing the user location, with a location key
+   *   that contains the lat / lng coordinates.
+   */
+  async _getLocation() {
+    log.info("_getLocation called");
+    let fetchOpts = { headers: { "Content-Type": "application/json" } };
+    let url = Services.urlFormatter.formatURLPref("geo.provider.network.url");
+    let req = await this._fetchTimeout(url, fetchOpts, lazy.networkTimeout);
+    let result = await req.json();
+    log.info("_getLocation returning", result);
+    return result;
+  }
+
+  /**
+   * Return the users current region using
+   * request that is used for GeoLocation requests.
+   *
+   * @returns {String}
+   *   A 2 character string representing a region.
+   */
+  async _getRegionLocally() {
+    let { location } = await this._getLocation();
+    return this._geoCode(location);
+  }
+
+  /**
+   * Take a location and return the region code for that location
+   * by looking up the coordinates in geojson map files.
+   * Inspired by https://github.com/mozilla/ichnaea/blob/874e8284f0dfa1868e79aae64e14707eed660efe/ichnaea/geocode.py#L114
+   *
+   * @param {Object} location
+   *   A location object containing lat + lng coordinates.
+   *
+   * @returns {String}
+   *   A 2 character string representing a region.
+   */
+  async _geoCode(location) {
+    let plainMap = await this._getPlainMap();
+    let polygons = this._getPolygonsContainingPoint(location, plainMap);
+    if (polygons.length == 1) {
+      log.info("Found in single exact region");
+      return polygons[0].properties.alpha2;
+    }
+    if (polygons.length) {
+      log.info("Found in ", polygons.length, "overlapping exact regions");
+      return this._findFurthest(location, polygons);
+    }
+
+    // We haven't found a match in the exact map, use the buffered map
+    // to see if the point is close to a region.
+    let bufferedMap = await this._getBufferedMap();
+    polygons = this._getPolygonsContainingPoint(location, bufferedMap);
+
+    if (polygons.length === 1) {
+      log.info("Found in single buffered region");
+      return polygons[0].properties.alpha2;
+    }
+
+    // Matched more than one region, which one of those regions
+    // is it closest to without the buffer.
+    if (polygons.length) {
+      log.info("Found in ", polygons.length, "overlapping buffered regions");
+      let regions = polygons.map(polygon => polygon.properties.alpha2);
+      let unBufferedRegions = plainMap.features.filter(feature =>
+        regions.includes(feature.properties.alpha2)
+      );
+      return this._findClosest(location, unBufferedRegions);
+    }
+    return null;
+  }
+
+  /**
+   * Find all the polygons that contain a single point, return
+   * an array of those polygons along with the region that
+   * they define
+   *
+   * @param {Object} point
+   *   A lat + lng coordinate.
+   * @param {Object} map
+   *   Geojson object that defined seperate regions with a list
+   *   of polygons.
+   *
+   * @returns {Array}
+   *   An array of polygons that contain the point, along with the
+   *   region they define.
+   */
+  _getPolygonsContainingPoint(point, map) {
+    let polygons = [];
+    for (const feature of map.features) {
+      let coords = feature.geometry.coordinates;
+      if (feature.geometry.type === "Polygon") {
+        if (this._polygonInPoint(point, coords[0])) {
+          polygons.push(feature);
+        }
+      } else if (feature.geometry.type === "MultiPolygon") {
+        for (const innerCoords of coords) {
+          if (this._polygonInPoint(point, innerCoords[0])) {
+            polygons.push(feature);
+          }
+        }
+      }
+    }
+    return polygons;
+  }
+
+  /**
+   * Find the largest distance between a point and any of the points that
+   * make up an array of regions.
+   *
+   * @param {Object} location
+   *   A lat + lng coordinate.
+   * @param {Array} regions
+   *   An array of GeoJSON region definitions.
+   *
+   * @returns {String}
+   *   A 2 character string representing a region.
+   */
+  _findFurthest(location, regions) {
+    let max = { distance: 0, region: null };
+    this._traverse(regions, ({ lat, lng, region }) => {
+      let distance = this._distanceBetween(location, { lng, lat });
+      if (distance > max.distance) {
+        max = { distance, region };
+      }
+    });
+    return max.region;
+  }
+
+  /**
+   * Find the smallest distance between a point and any of the points that
+   * make up an array of regions.
+   *
+   * @param {Object} location
+   *   A lat + lng coordinate.
+   * @param {Array} regions
+   *   An array of GeoJSON region definitions.
+   *
+   * @returns {String}
+   *   A 2 character string representing a region.
+   */
+  _findClosest(location, regions) {
+    let min = { distance: Infinity, region: null };
+    this._traverse(regions, ({ lat, lng, region }) => {
+      let distance = this._distanceBetween(location, { lng, lat });
+      if (distance < min.distance) {
+        min = { distance, region };
+      }
+    });
+    return min.region;
+  }
+
+  /**
+   * Utility function to loop over all the coordinate points in an
+   * array of polygons and call a function on them.
+   *
+   * @param {Array} regions
+   *   An array of GeoJSON region definitions.
+   * @param {Function} fun
+   *   Function to call on individual coordinates.
+   */
+  _traverse(regions, fun) {
+    for (const region of regions) {
+      if (region.geometry.type === "Polygon") {
+        for (const [lng, lat] of region.geometry.coordinates[0]) {
+          fun({ lat, lng, region: region.properties.alpha2 });
+        }
+      } else if (region.geometry.type === "MultiPolygon") {
+        for (const innerCoords of region.geometry.coordinates) {
+          for (const [lng, lat] of innerCoords[0]) {
+            fun({ lat, lng, region: region.properties.alpha2 });
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * Check whether a point is contained within a polygon using the
+   * point in polygon algorithm:
+   * https://en.wikipedia.org/wiki/Point_in_polygon
+   * This casts a ray from the point and counts how many times
+   * that ray intersects with the polygons borders, if it is
+   * an odd number of times the point is inside the polygon.
+   *
+   * @param {Object} location
+   *   A lat + lng coordinate.
+   * @param {Object} polygon
+   *   Array of coordinates that define the boundaries of a polygon.
+   *
+   * @returns {boolean}
+   *   Whether the point is within the polygon.
+   */
+  _polygonInPoint({ lng, lat }, poly) {
+    let inside = false;
+    // For each edge of the polygon.
+    for (let i = 0, j = poly.length - 1; i < poly.length; j = i++) {
+      let xi = poly[i][0];
+      let yi = poly[i][1];
+      let xj = poly[j][0];
+      let yj = poly[j][1];
+      // Does a ray cast from the point intersect with this polygon edge.
+      let intersect =
+        yi > lat != yj > lat && lng < ((xj - xi) * (lat - yi)) / (yj - yi) + xi;
+      // If so toggle result, an odd number of intersections
+      // means the point is inside.
+      if (intersect) {
+        inside = !inside;
+      }
+    }
+    return inside;
+  }
+
+  /**
+   * Find the distance between 2 points.
+   *
+   * @param {Object} p1
+   *   A lat + lng coordinate.
+   * @param {Object} p2
+   *   A lat + lng coordinate.
+   *
+   * @returns {int}
+   *   The distance between the 2 points.
+   */
+  _distanceBetween(p1, p2) {
+    return Math.hypot(p2.lng - p1.lng, p2.lat - p1.lat);
+  }
+
+  /**
+   * A wrapper around fetch that implements a timeout, will throw
+   * a TIMEOUT error if the request is not completed in time.
+   *
+   * @param {String} url
+   *   The time url to fetch.
+   * @param {Object} opts
+   *   The options object passed to the call to fetch.
+   * @param {int} timeout
+   *   The time in ms to wait for the request to complete.
+   */
+  async _fetchTimeout(url, opts, timeout) {
+    let controller = new AbortController();
+    opts.signal = controller.signal;
+    return Promise.race([fetch(url, opts), this._timeout(timeout, controller)]);
+  }
+
+  /**
+   * Implement the timeout for network requests. This will be run for
+   * all network requests, but the error will only be returned if it
+   * completes first.
+   *
+   * @param {int} timeout
+   *   The time in ms to wait for the request to complete.
+   * @param {Object} controller
+   *   The AbortController passed to the fetch request that
+   *   allows us to abort the request.
+   */
+  async _timeout(timeout, controller) {
+    await new Promise(resolve => lazy.setTimeout(resolve, timeout));
+    if (controller) {
+      // Yield so it is the TIMEOUT that is returned and not
+      // the result of the abort().
+      lazy.setTimeout(() => controller.abort(), 0);
+    }
+    throw new Error("TIMEOUT");
+  }
+
+  async _fetchWifiData() {
+    log.info("fetchWifiData called");
+    this.wifiService = Cc["@mozilla.org/wifi/monitor;1"].getService(
+      Ci.nsIWifiMonitor
+    );
+    this.wifiService.startWatching(this, false);
+
+    return new Promise(resolve => {
+      this._wifiDataPromise = resolve;
+    });
+  }
+
+  /**
+   * If the user is using geolocation then we will see frequent updates
+   * debounce those so we aren't processing them constantly.
+   *
+   * @returns {bool}
+   *   Whether we should continue the update check.
+   */
+  _needsUpdateCheck() {
+    let sinceUpdate = Math.round(Date.now() / 1000) - lazy.lastUpdated;
+    let needsUpdate = sinceUpdate >= lazy.updateDebounce;
+    if (!needsUpdate) {
+      log.info(`Ignoring update check, last seen ${sinceUpdate} seconds ago`);
+    }
+    return needsUpdate;
+  }
+
+  /**
+   * Dispatch a promise returning function to the main thread and
+   * resolve when it is completed.
+   */
+  _idleDispatch(fun) {
+    return new Promise(resolve => {
+      Services.tm.idleDispatchToMainThread(fun().then(resolve));
+    });
+  }
+
+  /**
+   * timerManager will call this periodically to update the region
+   * in case the user never users geolocation.
+   */
+  async _updateTimer() {
+    if (this._needsUpdateCheck()) {
+      await this._fetchRegion();
+    }
+  }
+
+  /**
+   * Called when we see geolocation updates.
+   * in case the user never users geolocation.
+   *
+   * @param {Object} location
+   *   A location object containing lat + lng coordinates.
+   *
+   */
+  async _seenLocation(location) {
+    log.info(`Got location update: ${location.lat}:${location.lng}`);
+    if (this._needsUpdateCheck()) {
+      let region = await this._geoCode(location);
+      if (region) {
+        this._setCurrentRegion(region);
+      }
+    }
+  }
+
+  onChange(accessPoints) {
+    log.info("onChange called");
+    if (!accessPoints || !this._wifiDataPromise) {
+      return;
+    }
+
+    if (this.wifiService) {
+      this.wifiService.stopWatching(this);
+      this.wifiService = null;
+    }
+
+    if (this._wifiDataPromise) {
+      let data = lazy.LocationHelper.formatWifiAccessPoints(accessPoints);
+      this._wifiDataPromise(data);
+      this._wifiDataPromise = null;
+    }
+  }
+
+  observe(aSubject, aTopic, aData) {
+    log.info(`Observed ${aTopic}`);
+    switch (aTopic) {
+      case GEOLOCATION_TOPIC:
+        // aSubject from GeoLocation.cpp will be a GeoPosition
+        // DOM Object, but from tests we will receive a
+        // wrappedJSObject so handle both here.
+        let coords = aSubject.coords || aSubject.wrappedJSObject.coords;
+        this._seenLocation({
+          lat: coords.latitude,
+          lng: coords.longitude,
+        });
+        break;
+    }
+  }
+
+  // For tests to create blank new instances.
+  newInstance() {
+    return new RegionDetector();
+  }
+}
+
+export let Region = new RegionDetector();
+Region.init();
+
+// A method that tries to determine if this user is in a US geography.
+function isUSTimezone() {
+  // Timezone assumptions! We assume that if the system clock's timezone is
+  // between Newfoundland and Hawaii, that the user is in North America.
+
+  // This includes all of South America as well, but we have relatively few
+  // en-US users there, so that's OK.
+
+  // 150 minutes = 2.5 hours (UTC-2.5), which is
+  // Newfoundland Daylight Time (http://www.timeanddate.com/time/zones/ndt)
+
+  // 600 minutes = 10 hours (UTC-10), which is
+  // Hawaii-Aleutian Standard Time (http://www.timeanddate.com/time/zones/hast)
+
+  let UTCOffset = new Date().getTimezoneOffset();
+  return UTCOffset >= 150 && UTCOffset <= 600;
+}