Bug 1916946 - Remove 'private_browsing.window_open_during_teardown' telemetry. r=firefox-desktop-core-reviewers ,mconley

This reverts commit 90baa7558e4bb31de60d8a4604ca965e4f8c6485.

Differential Revision: https://phabricator.services.mozilla.com/D221457

browser/components/privatebrowsing/PBMExitStatus.sys.mjs

@@ -1,89 +0,0 @@
-/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* vim: set ts=2 et sw=2 tw=80: */
-/* 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/. */
-/* eslint-env mozilla/browser-window */
-
-const lazy = {};
-
-ChromeUtils.defineESModuleGetters(lazy, {
-  PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
-});
-
-/**
- * Helper for determining whether we're in the process of tearing down a
- * private browsing session. Teardown is started when closing of the last
- * private browsing window and stops once the last private browsing Browsing
- * Context has been discarded.
- * If a new private browsing window is opened during teardown telemetry is
- * collected.
- */
-export const PBMExitStatus = {
-  _isInitialized: false,
-  // Keeps track of whether a PBM session is currently exiting.
-  _isExiting: false,
-
-  /**
-   * Initialize the helper. Needs to be called before isExiting.
-   */
-  init() {
-    // Init only once.
-    if (this._isInitialized) {
-      return;
-    }
-    this._isInitialized = true;
-
-    Services.obs.addObserver(this, "last-pb-context-exiting-granted");
-    Services.obs.addObserver(this, "last-pb-context-exited");
-
-    Services.ww.registerNotification(this);
-  },
-
-  /**
-   * Handler for PBM exited message.
-   */
-  _handlePrivateBrowsingExitStop() {
-    // If we didn't see an exit start message don't record anything. This is for
-    // skipping features like the PBM reset button which directly dispatches
-    // "last-pb-context-exited" without all PBM windows being closed.
-    if (!this._isExiting) {
-      return;
-    }
-    this._isExiting = false;
-
-    // Increase counter for total private browsing sessions.
-    Glean.privateBrowsing.windowOpenDuringTeardown.addToDenominator(1);
-  },
-
-  /**
-   * Handler for new chrome windows opened. Collects telemetry if we hit the PBM
-   * teardown race condition.
-   * @param {ChromeWindow} subject - The Chrome window that has been opened.
-   */
-  _handleDomWindowOpened(subject) {
-    if (
-      !this._isExiting ||
-      !lazy.PrivateBrowsingUtils.isWindowPrivate(subject)
-    ) {
-      return;
-    }
-    // Set exiting flag to false. We don't expect to see a
-    // "last-pb-context-exited" message now that a new PBM window has been
-    // opened. The PBM session continues.
-    this._isExiting = false;
-    // Private browsing window opened while we're exiting private browsing.
-    // Increase counter for race condition.
-    Glean.privateBrowsing.windowOpenDuringTeardown.addToNumerator(1);
-  },
-
-  observe(subject, topic) {
-    if (topic == "last-pb-context-exiting-granted") {
-      this._isExiting = true;
-    } else if (topic == "last-pb-context-exited") {
-      this._handlePrivateBrowsingExitStop();
-    } else if (topic == "domwindowopened") {
-      this._handleDomWindowOpened(subject);
-    }
-  },
-};

browser/components/privatebrowsing/metrics.yaml

@@ -48,21 +48,3 @@ private_browsing.reset_pbm:
     notification_emails:
       - pbz@mozilla.com
     expires: never
-private_browsing:
-  window_open_during_teardown:
-    type: rate
-    description: >
-      Numerator: How often a new private browsing window is opened while the old
-      private browsing session is still being shut down.
-      Denominator: How many private browsing sessions (are fully exited).
-      Rate: Of all private browsing sessions, how often do we run into the race
-      condition.
-    bugs:
-      - https://bugzilla.mozilla.org/show_bug.cgi?id=1900840
-    data_reviews:
-      - https://bugzilla.mozilla.org/show_bug.cgi?id=1900840
-    data_sensitivity:
-      - interaction
-    notification_emails:
-      - pbz@mozilla.com
-    expires: 133

browser/components/privatebrowsing/moz.build

@@ -11,7 +11,6 @@ BROWSER_CHROME_MANIFESTS += [
 JAR_MANIFESTS += ["jar.mn"]
 
 EXTRA_JS_MODULES += [
-    "PBMExitStatus.sys.mjs",
     "ResetPBMPanel.sys.mjs",
 ]