Adding upstream version 110.0.1.upstream/110.0.1upstream

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

1 files changed, 1639 insertions, 0 deletions

diff --git a/browser/base/content/browser-addons.js b/browser/base/content/browser-addons.js
new file mode 100644
index 0000000000..f37428aa5c
--- /dev/null
+++ b/browser/base/content/browser-addons.js
@@ -0,0 +1,1639 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+ * 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 file is loaded into the browser window scope.
+/* eslint-env mozilla/browser-window */
+
+const lazy = {};
+
+ChromeUtils.defineModuleGetter(
+  lazy,
+  "ExtensionParent",
+  "resource://gre/modules/ExtensionParent.jsm"
+);
+ChromeUtils.defineModuleGetter(
+  lazy,
+  "OriginControls",
+  "resource://gre/modules/ExtensionPermissions.jsm"
+);
+ChromeUtils.defineModuleGetter(
+  lazy,
+  "ExtensionPermissions",
+  "resource://gre/modules/ExtensionPermissions.jsm"
+);
+ChromeUtils.defineESModuleGetters(lazy, {
+  SITEPERMS_ADDON_TYPE:
+    "resource://gre/modules/addons/siteperms-addon-utils.sys.mjs",
+});
+
+customElements.define(
+  "addon-progress-notification",
+  class MozAddonProgressNotification extends customElements.get(
+    "popupnotification"
+  ) {
+    show() {
+      super.show();
+      this.progressmeter = document.getElementById(
+        "addon-progress-notification-progressmeter"
+      );
+
+      this.progresstext = document.getElementById(
+        "addon-progress-notification-progresstext"
+      );
+
+      if (!this.notification) {
+        return;
+      }
+
+      this.notification.options.installs.forEach(function(aInstall) {
+        aInstall.addListener(this);
+      }, this);
+
+      // Calling updateProgress can sometimes cause this notification to be
+      // removed in the middle of refreshing the notification panel which
+      // makes the panel get refreshed again. Just initialise to the
+      // undetermined state and then schedule a proper check at the next
+      // opportunity
+      this.setProgress(0, -1);
+      this._updateProgressTimeout = setTimeout(
+        this.updateProgress.bind(this),
+        0
+      );
+    }
+
+    disconnectedCallback() {
+      this.destroy();
+    }
+
+    destroy() {
+      if (!this.notification) {
+        return;
+      }
+      this.notification.options.installs.forEach(function(aInstall) {
+        aInstall.removeListener(this);
+      }, this);
+
+      clearTimeout(this._updateProgressTimeout);
+    }
+
+    setProgress(aProgress, aMaxProgress) {
+      if (aMaxProgress == -1) {
+        this.progressmeter.removeAttribute("value");
+      } else {
+        this.progressmeter.setAttribute(
+          "value",
+          (aProgress * 100) / aMaxProgress
+        );
+      }
+
+      let now = Date.now();
+
+      if (!this.notification.lastUpdate) {
+        this.notification.lastUpdate = now;
+        this.notification.lastProgress = aProgress;
+        return;
+      }
+
+      let delta = now - this.notification.lastUpdate;
+      if (delta < 400 && aProgress < aMaxProgress) {
+        return;
+      }
+
+      // Set min. time delta to avoid division by zero in the upcoming speed calculation
+      delta = Math.max(delta, 400);
+      delta /= 1000;
+
+      // This algorithm is the same used by the downloads code.
+      let speed = (aProgress - this.notification.lastProgress) / delta;
+      if (this.notification.speed) {
+        speed = speed * 0.9 + this.notification.speed * 0.1;
+      }
+
+      this.notification.lastUpdate = now;
+      this.notification.lastProgress = aProgress;
+      this.notification.speed = speed;
+
+      let status = null;
+      [status, this.notification.last] = DownloadUtils.getDownloadStatus(
+        aProgress,
+        aMaxProgress,
+        speed,
+        this.notification.last
+      );
+      this.progresstext.setAttribute("value", status);
+      this.progresstext.setAttribute("tooltiptext", status);
+    }
+
+    cancel() {
+      let installs = this.notification.options.installs;
+      installs.forEach(function(aInstall) {
+        try {
+          aInstall.cancel();
+        } catch (e) {
+          // Cancel will throw if the download has already failed
+        }
+      }, this);
+
+      PopupNotifications.remove(this.notification);
+    }
+
+    updateProgress() {
+      if (!this.notification) {
+        return;
+      }
+
+      let downloadingCount = 0;
+      let progress = 0;
+      let maxProgress = 0;
+
+      this.notification.options.installs.forEach(function(aInstall) {
+        if (aInstall.maxProgress == -1) {
+          maxProgress = -1;
+        }
+        progress += aInstall.progress;
+        if (maxProgress >= 0) {
+          maxProgress += aInstall.maxProgress;
+        }
+        if (aInstall.state < AddonManager.STATE_DOWNLOADED) {
+          downloadingCount++;
+        }
+      });
+
+      if (downloadingCount == 0) {
+        this.destroy();
+        this.progressmeter.removeAttribute("value");
+        let status = gNavigatorBundle.getString("addonDownloadVerifying");
+        this.progresstext.setAttribute("value", status);
+        this.progresstext.setAttribute("tooltiptext", status);
+      } else {
+        this.setProgress(progress, maxProgress);
+      }
+    }
+
+    onDownloadProgress() {
+      this.updateProgress();
+    }
+
+    onDownloadFailed() {
+      this.updateProgress();
+    }
+
+    onDownloadCancelled() {
+      this.updateProgress();
+    }
+
+    onDownloadEnded() {
+      this.updateProgress();
+    }
+  }
+);
+
+// Removes a doorhanger notification if all of the installs it was notifying
+// about have ended in some way.
+function removeNotificationOnEnd(notification, installs) {
+  let count = installs.length;
+
+  function maybeRemove(install) {
+    install.removeListener(this);
+
+    if (--count == 0) {
+      // Check that the notification is still showing
+      let current = PopupNotifications.getNotification(
+        notification.id,
+        notification.browser
+      );
+      if (current === notification) {
+        notification.remove();
+      }
+    }
+  }
+
+  for (let install of installs) {
+    install.addListener({
+      onDownloadCancelled: maybeRemove,
+      onDownloadFailed: maybeRemove,
+      onInstallFailed: maybeRemove,
+      onInstallEnded: maybeRemove,
+    });
+  }
+}
+
+var gXPInstallObserver = {
+  _findChildShell(aDocShell, aSoughtShell) {
+    if (aDocShell == aSoughtShell) {
+      return aDocShell;
+    }
+
+    var node = aDocShell.QueryInterface(Ci.nsIDocShellTreeItem);
+    for (var i = 0; i < node.childCount; ++i) {
+      var docShell = node.getChildAt(i);
+      docShell = this._findChildShell(docShell, aSoughtShell);
+      if (docShell == aSoughtShell) {
+        return docShell;
+      }
+    }
+    return null;
+  },
+
+  _getBrowser(aDocShell) {
+    for (let browser of gBrowser.browsers) {
+      if (this._findChildShell(browser.docShell, aDocShell)) {
+        return browser;
+      }
+    }
+    return null;
+  },
+
+  pendingInstalls: new WeakMap(),
+
+  showInstallConfirmation(browser, installInfo, height = undefined) {
+    // If the confirmation notification is already open cache the installInfo
+    // and the new confirmation will be shown later
+    if (
+      PopupNotifications.getNotification("addon-install-confirmation", browser)
+    ) {
+      let pending = this.pendingInstalls.get(browser);
+      if (pending) {
+        pending.push(installInfo);
+      } else {
+        this.pendingInstalls.set(browser, [installInfo]);
+      }
+      return;
+    }
+
+    let showNextConfirmation = () => {
+      // Make sure the browser is still alive.
+      if (!gBrowser.browsers.includes(browser)) {
+        return;
+      }
+
+      let pending = this.pendingInstalls.get(browser);
+      if (pending && pending.length) {
+        this.showInstallConfirmation(browser, pending.shift());
+      }
+    };
+
+    // If all installs have already been cancelled in some way then just show
+    // the next confirmation
+    if (
+      installInfo.installs.every(i => i.state != AddonManager.STATE_DOWNLOADED)
+    ) {
+      showNextConfirmation();
+      return;
+    }
+
+    // Make notifications persistent
+    var options = {
+      displayURI: installInfo.originatingURI,
+      persistent: true,
+      hideClose: true,
+    };
+
+    if (gUnifiedExtensions.isEnabled) {
+      options.popupOptions = {
+        position: "bottomright topright",
+      };
+    }
+
+    let acceptInstallation = () => {
+      for (let install of installInfo.installs) {
+        install.install();
+      }
+      installInfo = null;
+
+      Services.telemetry
+        .getHistogramById("SECURITY_UI")
+        .add(
+          Ci.nsISecurityUITelemetry.WARNING_CONFIRM_ADDON_INSTALL_CLICK_THROUGH
+        );
+    };
+
+    let cancelInstallation = () => {
+      if (installInfo) {
+        for (let install of installInfo.installs) {
+          // The notification may have been closed because the add-ons got
+          // cancelled elsewhere, only try to cancel those that are still
+          // pending install.
+          if (install.state != AddonManager.STATE_CANCELLED) {
+            install.cancel();
+          }
+        }
+      }
+
+      showNextConfirmation();
+    };
+
+    let unsigned = installInfo.installs.filter(
+      i => i.addon.signedState <= AddonManager.SIGNEDSTATE_MISSING
+    );
+    let someUnsigned =
+      !!unsigned.length && unsigned.length < installInfo.installs.length;
+
+    options.eventCallback = aEvent => {
+      switch (aEvent) {
+        case "removed":
+          cancelInstallation();
+          break;
+        case "shown":
+          let addonList = document.getElementById(
+            "addon-install-confirmation-content"
+          );
+          while (addonList.firstChild) {
+            addonList.firstChild.remove();
+          }
+
+          for (let install of installInfo.installs) {
+            let container = document.createXULElement("hbox");
+
+            let name = document.createXULElement("label");
+            name.setAttribute("value", install.addon.name);
+            name.setAttribute("class", "addon-install-confirmation-name");
+            container.appendChild(name);
+
+            if (
+              someUnsigned &&
+              install.addon.signedState <= AddonManager.SIGNEDSTATE_MISSING
+            ) {
+              let unsignedLabel = document.createXULElement("label");
+              unsignedLabel.setAttribute(
+                "value",
+                gNavigatorBundle.getString("addonInstall.unsigned")
+              );
+              unsignedLabel.setAttribute(
+                "class",
+                "addon-install-confirmation-unsigned"
+              );
+              container.appendChild(unsignedLabel);
+            }
+
+            addonList.appendChild(container);
+          }
+          break;
+      }
+    };
+
+    options.learnMoreURL = Services.urlFormatter.formatURLPref(
+      "app.support.baseURL"
+    );
+
+    let messageString;
+    let notification = document.getElementById(
+      "addon-install-confirmation-notification"
+    );
+    if (unsigned.length == installInfo.installs.length) {
+      // None of the add-ons are verified
+      messageString = gNavigatorBundle.getString(
+        "addonConfirmInstallUnsigned.message"
+      );
+      notification.setAttribute("warning", "true");
+      options.learnMoreURL += "unsigned-addons";
+    } else if (!unsigned.length) {
+      // All add-ons are verified or don't need to be verified
+      messageString = gNavigatorBundle.getString("addonConfirmInstall.message");
+      notification.removeAttribute("warning");
+      options.learnMoreURL += "find-and-install-add-ons";
+    } else {
+      // Some of the add-ons are unverified, the list of names will indicate
+      // which
+      messageString = gNavigatorBundle.getString(
+        "addonConfirmInstallSomeUnsigned.message"
+      );
+      notification.setAttribute("warning", "true");
+      options.learnMoreURL += "unsigned-addons";
+    }
+
+    let brandBundle = document.getElementById("bundle_brand");
+    let brandShortName = brandBundle.getString("brandShortName");
+
+    messageString = PluralForm.get(installInfo.installs.length, messageString);
+    messageString = messageString.replace("#1", brandShortName);
+    messageString = messageString.replace("#2", installInfo.installs.length);
+
+    let action = {
+      label: gNavigatorBundle.getString("addonInstall.acceptButton2.label"),
+      accessKey: gNavigatorBundle.getString(
+        "addonInstall.acceptButton2.accesskey"
+      ),
+      callback: acceptInstallation,
+    };
+
+    let secondaryAction = {
+      label: gNavigatorBundle.getString("addonInstall.cancelButton.label"),
+      accessKey: gNavigatorBundle.getString(
+        "addonInstall.cancelButton.accesskey"
+      ),
+      callback: () => {},
+    };
+
+    if (height) {
+      notification.style.minHeight = height + "px";
+    }
+
+    let tab = gBrowser.getTabForBrowser(browser);
+    if (tab) {
+      gBrowser.selectedTab = tab;
+    }
+
+    let popup = PopupNotifications.show(
+      browser,
+      "addon-install-confirmation",
+      messageString,
+      gUnifiedExtensions.getPopupAnchorID(browser, window),
+      action,
+      [secondaryAction],
+      options
+    );
+
+    removeNotificationOnEnd(popup, installInfo.installs);
+
+    Services.telemetry
+      .getHistogramById("SECURITY_UI")
+      .add(Ci.nsISecurityUITelemetry.WARNING_CONFIRM_ADDON_INSTALL);
+  },
+
+  // IDs of addon install related notifications
+  NOTIFICATION_IDS: [
+    "addon-install-blocked",
+    "addon-install-complete",
+    "addon-install-confirmation",
+    "addon-install-failed",
+    "addon-install-origin-blocked",
+    "addon-install-webapi-blocked",
+    "addon-install-policy-blocked",
+    "addon-progress",
+    "addon-webext-permissions",
+    "xpinstall-disabled",
+  ],
+
+  /**
+   * Remove all opened addon installation notifications
+   *
+   * @param {*} browser - Browser to remove notifications for
+   * @returns {boolean} - true if notifications have been removed.
+   */
+  removeAllNotifications(browser) {
+    let notifications = this.NOTIFICATION_IDS.map(id =>
+      PopupNotifications.getNotification(id, browser)
+    ).filter(notification => notification != null);
+
+    PopupNotifications.remove(notifications, true);
+
+    return !!notifications.length;
+  },
+
+  logWarningFullScreenInstallBlocked() {
+    // If notifications have been removed, log a warning to the website console
+    let consoleMsg = Cc["@mozilla.org/scripterror;1"].createInstance(
+      Ci.nsIScriptError
+    );
+    let message = gBrowserBundle.GetStringFromName(
+      "addonInstallFullScreenBlocked"
+    );
+    consoleMsg.initWithWindowID(
+      message,
+      gBrowser.currentURI.spec,
+      null,
+      0,
+      0,
+      Ci.nsIScriptError.warningFlag,
+      "FullScreen",
+      gBrowser.selectedBrowser.innerWindowID
+    );
+    Services.console.logMessage(consoleMsg);
+  },
+
+  observe(aSubject, aTopic, aData) {
+    var brandBundle = document.getElementById("bundle_brand");
+    var installInfo = aSubject.wrappedJSObject;
+    var browser = installInfo.browser;
+
+    // Make sure the browser is still alive.
+    if (!browser || !gBrowser.browsers.includes(browser)) {
+      return;
+    }
+
+    var messageString, action;
+    var brandShortName = brandBundle.getString("brandShortName");
+
+    var notificationID = aTopic;
+    // Make notifications persistent
+    var options = {
+      displayURI: installInfo.originatingURI,
+      persistent: true,
+      hideClose: true,
+      timeout: Date.now() + 30000,
+    };
+
+    if (gUnifiedExtensions.isEnabled) {
+      options.popupOptions = {
+        position: "bottomright topright",
+      };
+    }
+
+    switch (aTopic) {
+      case "addon-install-disabled": {
+        notificationID = "xpinstall-disabled";
+        let secondaryActions = null;
+
+        if (Services.prefs.prefIsLocked("xpinstall.enabled")) {
+          messageString = gNavigatorBundle.getString(
+            "xpinstallDisabledMessageLocked"
+          );
+        } else {
+          messageString = gNavigatorBundle.getString(
+            "xpinstallDisabledMessage"
+          );
+
+          action = {
+            label: gNavigatorBundle.getString("xpinstallDisabledButton"),
+            accessKey: gNavigatorBundle.getString(
+              "xpinstallDisabledButton.accesskey"
+            ),
+            callback: function editPrefs() {
+              Services.prefs.setBoolPref("xpinstall.enabled", true);
+            },
+          };
+
+          secondaryActions = [
+            {
+              label: gNavigatorBundle.getString(
+                "addonInstall.cancelButton.label"
+              ),
+              accessKey: gNavigatorBundle.getString(
+                "addonInstall.cancelButton.accesskey"
+              ),
+              callback: () => {},
+            },
+          ];
+        }
+
+        PopupNotifications.show(
+          browser,
+          notificationID,
+          messageString,
+          gUnifiedExtensions.getPopupAnchorID(browser, window),
+          action,
+          secondaryActions,
+          options
+        );
+        break;
+      }
+      case "addon-install-fullscreen-blocked": {
+        // AddonManager denied installation because we are in DOM fullscreen
+        this.logWarningFullScreenInstallBlocked();
+        break;
+      }
+      case "addon-install-webapi-blocked":
+      case "addon-install-policy-blocked":
+      case "addon-install-origin-blocked": {
+        if (aTopic == "addon-install-policy-blocked") {
+          messageString = gNavigatorBundle.getString(
+            "addonDomainBlockedByPolicy"
+          );
+        } else {
+          messageString = gNavigatorBundle.getFormattedString(
+            "xpinstallPromptMessage",
+            [brandShortName]
+          );
+        }
+
+        if (Services.policies) {
+          let extensionSettings = Services.policies.getExtensionSettings("*");
+          if (
+            extensionSettings &&
+            "blocked_install_message" in extensionSettings
+          ) {
+            messageString += " " + extensionSettings.blocked_install_message;
+          }
+        }
+
+        options.removeOnDismissal = true;
+        options.persistent = false;
+
+        let secHistogram = Services.telemetry.getHistogramById("SECURITY_UI");
+        secHistogram.add(
+          Ci.nsISecurityUITelemetry.WARNING_ADDON_ASKING_PREVENTED
+        );
+        let popup = PopupNotifications.show(
+          browser,
+          notificationID,
+          messageString,
+          gUnifiedExtensions.getPopupAnchorID(browser, window),
+          null,
+          null,
+          options
+        );
+        removeNotificationOnEnd(popup, installInfo.installs);
+        break;
+      }
+      case "addon-install-blocked": {
+        // Dismiss the progress notification.  Note that this is bad if
+        // there are multiple simultaneous installs happening, see
+        // bug 1329884 for a longer explanation.
+        let progressNotification = PopupNotifications.getNotification(
+          "addon-progress",
+          browser
+        );
+        if (progressNotification) {
+          progressNotification.remove();
+        }
+
+        // The informational content differs somewhat for site permission
+        // add-ons. AOM no longer supports installing multiple addons,
+        // so the array handling here is vestigial.
+        let isSitePermissionAddon = installInfo.installs.every(
+          ({ addon }) => addon?.type === lazy.SITEPERMS_ADDON_TYPE
+        );
+        let hasHost = !!options.displayURI;
+
+        if (isSitePermissionAddon) {
+          messageString = gNavigatorBundle.getString(
+            "sitePermissionInstallFirstPrompt.header"
+          );
+        } else if (hasHost) {
+          messageString = gNavigatorBundle.getFormattedString(
+            "xpinstallPromptMessage.header",
+            ["<>"]
+          );
+          options.name = options.displayURI.displayHost;
+        } else {
+          messageString = gNavigatorBundle.getString(
+            "xpinstallPromptMessage.header.unknown"
+          );
+        }
+        // displayURI becomes it's own label, so we unset it for this panel. It will become part of the
+        // messageString above.
+        let displayURI = options.displayURI;
+        options.displayURI = undefined;
+
+        options.eventCallback = topic => {
+          if (topic !== "showing") {
+            return;
+          }
+          let doc = browser.ownerDocument;
+          let message = doc.getElementById("addon-install-blocked-message");
+          // We must remove any prior use of this panel message in this window.
+          while (message.firstChild) {
+            message.firstChild.remove();
+          }
+
+          if (isSitePermissionAddon) {
+            message.textContent = gNavigatorBundle.getString(
+              "sitePermissionInstallFirstPrompt.message"
+            );
+          } else if (hasHost) {
+            let text = gNavigatorBundle.getString(
+              "xpinstallPromptMessage.message"
+            );
+            let b = doc.createElementNS("http://www.w3.org/1999/xhtml", "b");
+            b.textContent = options.name;
+            let fragment = BrowserUIUtils.getLocalizedFragment(doc, text, b);
+            message.appendChild(fragment);
+          } else {
+            message.textContent = gNavigatorBundle.getString(
+              "xpinstallPromptMessage.message.unknown"
+            );
+          }
+
+          let article = isSitePermissionAddon
+            ? "site-permission-addons"
+            : "unlisted-extensions-risks";
+          let learnMore = doc.getElementById("addon-install-blocked-info");
+          learnMore.textContent = gNavigatorBundle.getString(
+            "xpinstallPromptMessage.learnMore"
+          );
+          learnMore.setAttribute(
+            "href",
+            Services.urlFormatter.formatURLPref("app.support.baseURL") + article
+          );
+        };
+
+        let secHistogram = Services.telemetry.getHistogramById("SECURITY_UI");
+        action = {
+          label: gNavigatorBundle.getString("xpinstallPromptMessage.install"),
+          accessKey: gNavigatorBundle.getString(
+            "xpinstallPromptMessage.install.accesskey"
+          ),
+          callback() {
+            secHistogram.add(
+              Ci.nsISecurityUITelemetry
+                .WARNING_ADDON_ASKING_PREVENTED_CLICK_THROUGH
+            );
+            installInfo.install();
+          },
+        };
+        let dontAllowAction = {
+          label: gNavigatorBundle.getString("xpinstallPromptMessage.dontAllow"),
+          accessKey: gNavigatorBundle.getString(
+            "xpinstallPromptMessage.dontAllow.accesskey"
+          ),
+          callback: () => {
+            for (let install of installInfo.installs) {
+              if (install.state != AddonManager.STATE_CANCELLED) {
+                install.cancel();
+              }
+            }
+            if (installInfo.cancel) {
+              installInfo.cancel();
+            }
+          },
+        };
+
+        let neverAllowCallback = () => {
+          SitePermissions.setForPrincipal(
+            browser.contentPrincipal,
+            "install",
+            SitePermissions.BLOCK
+          );
+          for (let install of installInfo.installs) {
+            if (install.state != AddonManager.STATE_CANCELLED) {
+              install.cancel();
+            }
+          }
+          if (installInfo.cancel) {
+            installInfo.cancel();
+          }
+        };
+
+        let neverAllowAction = {
+          label: gNavigatorBundle.getString(
+            "xpinstallPromptMessage.neverAllow"
+          ),
+          accessKey: gNavigatorBundle.getString(
+            "xpinstallPromptMessage.neverAllow.accesskey"
+          ),
+          callback: neverAllowCallback,
+        };
+
+        let neverAllowAndReportAction = {
+          label: gNavigatorBundle.getString(
+            "xpinstallPromptMessage.neverAllowAndReport"
+          ),
+          accessKey: gNavigatorBundle.getString(
+            "xpinstallPromptMessage.neverAllowAndReport.accesskey"
+          ),
+          callback: () => {
+            AMTelemetry.recordEvent({
+              method: "reportSuspiciousSite",
+              object: "suspiciousSite",
+              value: displayURI?.displayHost ?? "(unknown)",
+              extra: {},
+            });
+            neverAllowCallback();
+          },
+        };
+
+        secHistogram.add(
+          Ci.nsISecurityUITelemetry.WARNING_ADDON_ASKING_PREVENTED
+        );
+
+        let declineActions = [dontAllowAction, neverAllowAction];
+        if (isSitePermissionAddon) {
+          // Restrict this to site permission add-ons for now pending a decision
+          // from product about how to approach this for extensions.
+          declineActions.push(neverAllowAndReportAction);
+        }
+        let popup = PopupNotifications.show(
+          browser,
+          notificationID,
+          messageString,
+          gUnifiedExtensions.getPopupAnchorID(browser, window),
+          action,
+          declineActions,
+          options
+        );
+        removeNotificationOnEnd(popup, installInfo.installs);
+        break;
+      }
+      case "addon-install-started": {
+        let needsDownload = function needsDownload(aInstall) {
+          return aInstall.state != AddonManager.STATE_DOWNLOADED;
+        };
+        // If all installs have already been downloaded then there is no need to
+        // show the download progress
+        if (!installInfo.installs.some(needsDownload)) {
+          return;
+        }
+        notificationID = "addon-progress";
+        messageString = gNavigatorBundle.getString(
+          "addonDownloadingAndVerifying"
+        );
+        messageString = PluralForm.get(
+          installInfo.installs.length,
+          messageString
+        );
+        messageString = messageString.replace(
+          "#1",
+          installInfo.installs.length
+        );
+        options.installs = installInfo.installs;
+        options.contentWindow = browser.contentWindow;
+        options.sourceURI = browser.currentURI;
+        options.eventCallback = function(aEvent) {
+          switch (aEvent) {
+            case "removed":
+              options.contentWindow = null;
+              options.sourceURI = null;
+              break;
+          }
+        };
+        action = {
+          label: gNavigatorBundle.getString("addonInstall.acceptButton2.label"),
+          accessKey: gNavigatorBundle.getString(
+            "addonInstall.acceptButton2.accesskey"
+          ),
+          disabled: true,
+          callback: () => {},
+        };
+        let secondaryAction = {
+          label: gNavigatorBundle.getString("addonInstall.cancelButton.label"),
+          accessKey: gNavigatorBundle.getString(
+            "addonInstall.cancelButton.accesskey"
+          ),
+          callback: () => {
+            for (let install of installInfo.installs) {
+              if (install.state != AddonManager.STATE_CANCELLED) {
+                install.cancel();
+              }
+            }
+          },
+        };
+        let notification = PopupNotifications.show(
+          browser,
+          notificationID,
+          messageString,
+          gUnifiedExtensions.getPopupAnchorID(browser, window),
+          action,
+          [secondaryAction],
+          options
+        );
+        notification._startTime = Date.now();
+
+        break;
+      }
+      case "addon-install-failed": {
+        options.removeOnDismissal = true;
+        options.persistent = false;
+
+        // TODO This isn't terribly ideal for the multiple failure case
+        for (let install of installInfo.installs) {
+          let host;
+          try {
+            host = options.displayURI.host;
+          } catch (e) {
+            // displayURI might be missing or 'host' might throw for non-nsStandardURL nsIURIs.
+          }
+
+          if (!host) {
+            host =
+              install.sourceURI instanceof Ci.nsIStandardURL &&
+              install.sourceURI.host;
+          }
+
+          // Construct the l10n ID for the error, e.g. "addonInstallError-3"
+          let error =
+            host || install.error == 0
+              ? "addonInstallError"
+              : "addonLocalInstallError";
+          let args;
+          if (install.error < 0) {
+            // Append the error code for the installation failure to get the
+            // matching translation of the error. The error code is defined in
+            // AddonManager's _errors Map. Not all error codes listed there are
+            // translated, since errors that are only triggered during updates
+            // will never reach this code.
+            error += install.error;
+            args = [brandShortName, install.name];
+          } else if (
+            install.addon.blocklistState == Ci.nsIBlocklistService.STATE_BLOCKED
+          ) {
+            error += "Blocklisted";
+            args = [install.name];
+          } else {
+            error += "Incompatible";
+            args = [brandShortName, Services.appinfo.version, install.name];
+          }
+
+          if (
+            install.addon &&
+            !Services.policies.mayInstallAddon(install.addon)
+          ) {
+            error = "addonInstallBlockedByPolicy";
+            let extensionSettings = Services.policies.getExtensionSettings(
+              install.addon.id
+            );
+            let message = "";
+            if (
+              extensionSettings &&
+              "blocked_install_message" in extensionSettings
+            ) {
+              message = " " + extensionSettings.blocked_install_message;
+            }
+            args = [install.name, install.addon.id, message];
+          }
+
+          // Add Learn More link when refusing to install an unsigned add-on
+          if (install.error == AddonManager.ERROR_SIGNEDSTATE_REQUIRED) {
+            options.learnMoreURL =
+              Services.urlFormatter.formatURLPref("app.support.baseURL") +
+              "unsigned-addons";
+          }
+
+          messageString = gNavigatorBundle.getFormattedString(error, args);
+
+          PopupNotifications.show(
+            browser,
+            notificationID,
+            messageString,
+            gUnifiedExtensions.getPopupAnchorID(browser, window),
+            action,
+            null,
+            options
+          );
+
+          // Can't have multiple notifications with the same ID, so stop here.
+          break;
+        }
+        this._removeProgressNotification(browser);
+        break;
+      }
+      case "addon-install-confirmation": {
+        let showNotification = () => {
+          let height = undefined;
+
+          if (PopupNotifications.isPanelOpen) {
+            let rect = document
+              .getElementById("addon-progress-notification")
+              .getBoundingClientRect();
+            height = rect.height;
+          }
+
+          this._removeProgressNotification(browser);
+          this.showInstallConfirmation(browser, installInfo, height);
+        };
+
+        let progressNotification = PopupNotifications.getNotification(
+          "addon-progress",
+          browser
+        );
+        if (progressNotification) {
+          let downloadDuration = Date.now() - progressNotification._startTime;
+          let securityDelay =
+            Services.prefs.getIntPref("security.dialog_enable_delay") -
+            downloadDuration;
+          if (securityDelay > 0) {
+            setTimeout(() => {
+              // The download may have been cancelled during the security delay
+              if (
+                PopupNotifications.getNotification("addon-progress", browser)
+              ) {
+                showNotification();
+              }
+            }, securityDelay);
+            break;
+          }
+        }
+        showNotification();
+        break;
+      }
+      case "addon-install-complete": {
+        let secondaryActions = null;
+        let numAddons = installInfo.installs.length;
+
+        if (numAddons == 1) {
+          messageString = gNavigatorBundle.getFormattedString(
+            "addonInstalled",
+            [installInfo.installs[0].name]
+          );
+        } else {
+          messageString = gNavigatorBundle.getString("addonsGenericInstalled");
+          messageString = PluralForm.get(numAddons, messageString);
+          messageString = messageString.replace("#1", numAddons);
+        }
+        action = null;
+
+        options.removeOnDismissal = true;
+        options.persistent = false;
+
+        PopupNotifications.show(
+          browser,
+          notificationID,
+          messageString,
+          gUnifiedExtensions.getPopupAnchorID(browser, window),
+          action,
+          secondaryActions,
+          options
+        );
+        break;
+      }
+    }
+  },
+  _removeProgressNotification(aBrowser) {
+    let notification = PopupNotifications.getNotification(
+      "addon-progress",
+      aBrowser
+    );
+    if (notification) {
+      notification.remove();
+    }
+  },
+};
+
+var gExtensionsNotifications = {
+  initialized: false,
+  init() {
+    this.updateAlerts();
+    this.boundUpdate = this.updateAlerts.bind(this);
+    ExtensionsUI.on("change", this.boundUpdate);
+    this.initialized = true;
+  },
+
+  uninit() {
+    // uninit() can race ahead of init() in some cases, if that happens,
+    // we have no handler to remove.
+    if (!this.initialized) {
+      return;
+    }
+    ExtensionsUI.off("change", this.boundUpdate);
+  },
+
+  _createAddonButton(text, icon, callback) {
+    let button = document.createXULElement("toolbarbutton");
+    button.setAttribute("wrap", "true");
+    button.setAttribute("label", text);
+    button.setAttribute("tooltiptext", text);
+    const DEFAULT_EXTENSION_ICON =
+      "chrome://mozapps/skin/extensions/extensionGeneric.svg";
+    button.setAttribute("image", icon || DEFAULT_EXTENSION_ICON);
+    button.className = "addon-banner-item subviewbutton";
+
+    button.addEventListener("command", callback);
+    PanelUI.addonNotificationContainer.appendChild(button);
+  },
+
+  updateAlerts() {
+    let sideloaded = ExtensionsUI.sideloaded;
+    let updates = ExtensionsUI.updates;
+
+    let container = PanelUI.addonNotificationContainer;
+
+    while (container.firstChild) {
+      container.firstChild.remove();
+    }
+
+    let items = 0;
+    for (let update of updates) {
+      if (++items > 4) {
+        break;
+      }
+      let text = gNavigatorBundle.getFormattedString(
+        "webextPerms.updateMenuItem",
+        [update.addon.name]
+      );
+      this._createAddonButton(text, update.addon.iconURL, evt => {
+        ExtensionsUI.showUpdate(gBrowser, update);
+      });
+    }
+
+    let appName;
+    for (let addon of sideloaded) {
+      if (++items > 4) {
+        break;
+      }
+      if (!appName) {
+        let brandBundle = document.getElementById("bundle_brand");
+        appName = brandBundle.getString("brandShortName");
+      }
+
+      let text = gNavigatorBundle.getFormattedString(
+        "webextPerms.sideloadMenuItem",
+        [addon.name, appName]
+      );
+      this._createAddonButton(text, addon.iconURL, evt => {
+        // We need to hide the main menu manually because the toolbarbutton is
+        // removed immediately while processing this event, and PanelUI is
+        // unable to identify which panel should be closed automatically.
+        PanelUI.hide();
+        ExtensionsUI.showSideloaded(gBrowser, addon);
+      });
+    }
+  },
+};
+
+var BrowserAddonUI = {
+  async promptRemoveExtension(addon) {
+    let { name } = addon;
+    let title = await document.l10n.formatValue("addon-removal-title", {
+      name,
+    });
+    let { getFormattedString, getString } = gNavigatorBundle;
+    let btnTitle = getString("webext.remove.confirmation.button");
+    let {
+      BUTTON_TITLE_IS_STRING: titleString,
+      BUTTON_TITLE_CANCEL: titleCancel,
+      BUTTON_POS_0,
+      BUTTON_POS_1,
+      confirmEx,
+    } = Services.prompt;
+    let btnFlags = BUTTON_POS_0 * titleString + BUTTON_POS_1 * titleCancel;
+    let checkboxState = { value: false };
+    let checkboxMessage = null;
+
+    // Enable abuse report checkbox in the remove extension dialog,
+    // if enabled by the about:config prefs and the addon type
+    // is currently supported.
+    if (
+      gAddonAbuseReportEnabled &&
+      ["extension", "theme"].includes(addon.type)
+    ) {
+      checkboxMessage = await document.l10n.formatValue(
+        "addon-removal-abuse-report-checkbox"
+      );
+    }
+
+    let message = null;
+
+    if (!Services.prefs.getBoolPref("prompts.windowPromptSubDialog", false)) {
+      message = getFormattedString("webext.remove.confirmation.message", [
+        name,
+        document.getElementById("bundle_brand").getString("brandShorterName"),
+      ]);
+    }
+
+    let result = confirmEx(
+      window,
+      title,
+      message,
+      btnFlags,
+      btnTitle,
+      /* button1 */ null,
+      /* button2 */ null,
+      checkboxMessage,
+      checkboxState
+    );
+
+    return { remove: result === 0, report: checkboxState.value };
+  },
+
+  async reportAddon(addonId, reportEntryPoint) {
+    let addon = addonId && (await AddonManager.getAddonByID(addonId));
+    if (!addon) {
+      return;
+    }
+
+    const win = await BrowserOpenAddonsMgr("addons://list/extension");
+
+    win.openAbuseReport({ addonId, reportEntryPoint });
+  },
+
+  async removeAddon(addonId, eventObject) {
+    let addon = addonId && (await AddonManager.getAddonByID(addonId));
+    if (!addon || !(addon.permissions & AddonManager.PERM_CAN_UNINSTALL)) {
+      return;
+    }
+
+    let { remove, report } = await this.promptRemoveExtension(addon);
+
+    AMTelemetry.recordActionEvent({
+      object: eventObject,
+      action: "uninstall",
+      value: remove ? "accepted" : "cancelled",
+      extra: { addonId },
+    });
+
+    if (remove) {
+      // Leave the extension in pending uninstall if we are also reporting the
+      // add-on.
+      await addon.uninstall(report);
+
+      if (report) {
+        await this.reportAddon(addon.id, "uninstall");
+      }
+    }
+  },
+
+  async manageAddon(addonId, eventObject) {
+    let addon = addonId && (await AddonManager.getAddonByID(addonId));
+    if (!addon) {
+      return;
+    }
+
+    BrowserOpenAddonsMgr("addons://detail/" + encodeURIComponent(addon.id));
+    AMTelemetry.recordActionEvent({
+      object: eventObject,
+      action: "manage",
+      extra: { addonId: addon.id },
+    });
+  },
+};
+
+// We must declare `gUnifiedExtensions` using `var` below to avoid a
+// "redeclaration" syntax error.
+var gUnifiedExtensions = {
+  _initialized: false,
+
+  // We use a `<deck>` in the extension items to show/hide messages below each
+  // extension name. We have a default message for origin controls, and
+  // optionally a second message shown on hover, which describes the action
+  // (when clicking on the action button). We have another message shown when
+  // the menu button is hovered/focused. The constants below define the indexes
+  // of each message in the `<deck>`.
+  MESSAGE_DECK_INDEX_DEFAULT: 0,
+  MESSAGE_DECK_INDEX_HOVER: 1,
+  MESSAGE_DECK_INDEX_MENU_HOVER: 2,
+
+  init() {
+    if (this._initialized) {
+      return;
+    }
+
+    if (this.isEnabled) {
+      this._button = document.getElementById("unified-extensions-button");
+      // TODO: Bug 1778684 - Auto-hide button when there is no active extension.
+      this._button.hidden = false;
+
+      document
+        .getElementById("nav-bar")
+        .setAttribute("unifiedextensionsbuttonshown", true);
+
+      gBrowser.addTabsProgressListener(this);
+      window.addEventListener("TabSelect", () => this.updateAttention());
+
+      this.permListener = () => this.updateAttention();
+      lazy.ExtensionPermissions.addListener(this.permListener);
+
+      gNavToolbox.addEventListener("customizationstarting", this);
+    }
+
+    this._initialized = true;
+  },
+
+  uninit() {
+    if (this.permListener) {
+      lazy.ExtensionPermissions.removeListener(this.permListener);
+      this.permListener = null;
+    }
+    gNavToolbox.removeEventListener("customizationstarting", this);
+  },
+
+  get isEnabled() {
+    return Services.prefs.getBoolPref(
+      "extensions.unifiedExtensions.enabled",
+      false
+    );
+  },
+
+  onLocationChange(browser, webProgress, _request, _uri, flags) {
+    // Only update on top-level cross-document navigations in the selected tab.
+    if (
+      webProgress.isTopLevel &&
+      browser === gBrowser.selectedBrowser &&
+      !(flags & Ci.nsIWebProgressListener.LOCATION_CHANGE_SAME_DOCUMENT)
+    ) {
+      this.updateAttention();
+    }
+  },
+
+  // Update the attention indicator for the whole unified extensions button.
+  updateAttention() {
+    let attention = false;
+    for (let policy of this.getActivePolicies()) {
+      let widget = this.browserActionFor(policy)?.widget;
+
+      // Only show for extensions which are not already visible in the toolbar.
+      if (!widget || widget.areaType !== CustomizableUI.TYPE_TOOLBAR) {
+        if (lazy.OriginControls.getAttention(policy, window)) {
+          attention = true;
+          break;
+        }
+      }
+    }
+    this.button.toggleAttribute("attention", attention);
+    this.button.ownerDocument.l10n.setAttributes(
+      this.button,
+      attention
+        ? "unified-extensions-button-permissions-needed"
+        : "unified-extensions-button"
+    );
+  },
+
+  getPopupAnchorID(aBrowser, aWindow) {
+    if (this.isEnabled) {
+      const anchorID = "unified-extensions-button";
+      const attr = anchorID + "popupnotificationanchor";
+
+      if (!aBrowser[attr]) {
+        // A hacky way of setting the popup anchor outside the usual url bar
+        // icon box, similar to how it was done for CFR.
+        // See: https://searchfox.org/mozilla-central/rev/c5c002f81f08a73e04868e0c2bf0eb113f200b03/toolkit/modules/PopupNotifications.sys.mjs#40
+        aBrowser[attr] = aWindow.document.getElementById(
+          anchorID
+          // Anchor on the toolbar icon to position the popup right below the
+          // button.
+        ).firstElementChild;
+      }
+
+      return anchorID;
+    }
+
+    return "addons-notification-icon";
+  },
+
+  get button() {
+    return this._button;
+  },
+
+  /**
+   * Gets a list of active WebExtensionPolicy instances of type "extension",
+   * sorted alphabetically based on add-on's names. Optionally, filter out
+   * extensions with browser action.
+   *
+   * @param {bool} all When set to true (the default), return the list of all
+   *                   active policies, including the ones that have a
+   *                   browser action. Otherwise, extensions with browser
+   *                   action are filtered out.
+   * @returns {Array<WebExtensionPolicy>} An array of active policies.
+   */
+  getActivePolicies(all = true) {
+    let policies = WebExtensionPolicy.getActiveExtensions();
+    policies = policies.filter(policy => {
+      let { extension } = policy;
+      if (!policy.active || extension?.type !== "extension") {
+        return false;
+      }
+
+      // Ignore hidden and extensions that cannot access the current window
+      // (because of PB mode when we are in a private window), since users
+      // cannot do anything with those extensions anyway.
+      if (extension.isHidden || !policy.canAccessWindow(window)) {
+        return false;
+      }
+
+      return all || !extension.hasBrowserActionUI;
+    });
+
+    policies.sort((a, b) => a.name.localeCompare(b.name));
+    return policies;
+  },
+
+  /**
+   * Returns true when there are active extensions listed/shown in the unified
+   * extensions panel, and false otherwise (e.g. when extensions are pinned in
+   * the toolbar OR there are 0 active extensions).
+   *
+   * @returns {boolean} Whether there are extensions listed in the panel.
+   */
+  hasExtensionsInPanel() {
+    const policies = this.getActivePolicies();
+
+    return !!policies
+      .map(policy => this.browserActionFor(policy)?.widget)
+      .filter(widget => {
+        return (
+          !widget ||
+          widget?.areaType !== CustomizableUI.TYPE_TOOLBAR ||
+          widget?.forWindow(window).overflowed
+        );
+      }).length;
+  },
+
+  handleEvent(event) {
+    switch (event.type) {
+      case "ViewShowing":
+        this.onPanelViewShowing(event.target);
+        break;
+
+      case "ViewHiding":
+        this.onPanelViewHiding(event.target);
+        break;
+
+      case "customizationstarting":
+        this.panel.hidePopup();
+        break;
+    }
+  },
+
+  onPanelViewShowing(panelview) {
+    const list = panelview.querySelector(".unified-extensions-list");
+    // Only add extensions that do not have a browser action in this list since
+    // the extensions with browser action have CUI widgets and will appear in
+    // the panel (or toolbar) via the CUI mechanism.
+    const policies = this.getActivePolicies(/* all */ false);
+
+    for (const policy of policies) {
+      const item = document.createElement("unified-extensions-item");
+      item.setExtension(policy.extension);
+      list.appendChild(item);
+    }
+  },
+
+  onPanelViewHiding(panelview) {
+    const list = panelview.querySelector(".unified-extensions-list");
+    while (list.lastChild) {
+      list.lastChild.remove();
+    }
+  },
+
+  _panel: null,
+  get panel() {
+    // Lazy load the unified-extensions-panel panel the first time we need to
+    // display it.
+    if (!this._panel) {
+      let template = document.getElementById(
+        "unified-extensions-panel-template"
+      );
+      template.replaceWith(template.content);
+      this._panel = document.getElementById("unified-extensions-panel");
+      let customizationArea = this._panel.querySelector(
+        "#unified-extensions-area"
+      );
+      CustomizableUI.registerPanelNode(
+        customizationArea,
+        CustomizableUI.AREA_ADDONS
+      );
+      CustomizableUI.addPanelCloseListeners(this._panel);
+
+      // Lazy-load the l10n strings. Those strings are used for the CUI and
+      // non-CUI extensions in the unified extensions panel.
+      document
+        .getElementById("unified-extensions-context-menu")
+        .querySelectorAll("[data-lazy-l10n-id]")
+        .forEach(el => {
+          el.setAttribute("data-l10n-id", el.getAttribute("data-lazy-l10n-id"));
+          el.removeAttribute("data-lazy-l10n-id");
+        });
+    }
+    return this._panel;
+  },
+
+  async togglePanel(aEvent) {
+    if (!CustomizationHandler.isCustomizing()) {
+      if (aEvent) {
+        if (
+          // On MacOS, ctrl-click will send a context menu event from the
+          // widget, so we don't want to bring up the panel when ctrl key is
+          // pressed.
+          (aEvent.type == "mousedown" &&
+            (aEvent.button !== 0 ||
+              (AppConstants.platform === "macosx" && aEvent.ctrlKey))) ||
+          (aEvent.type === "keypress" &&
+            aEvent.charCode !== KeyEvent.DOM_VK_SPACE &&
+            aEvent.keyCode !== KeyEvent.DOM_VK_RETURN)
+        ) {
+          return;
+        }
+
+        // The button should directly open `about:addons` when the user does not
+        // have any active extensions listed in the unified extensions panel.
+        if (!this.hasExtensionsInPanel()) {
+          await BrowserOpenAddonsMgr("addons://discover/");
+          return;
+        }
+      }
+
+      let panel = this.panel;
+
+      if (!this._listView) {
+        this._listView = PanelMultiView.getViewNode(
+          document,
+          "unified-extensions-view"
+        );
+        this._listView.addEventListener("ViewShowing", this);
+        this._listView.addEventListener("ViewHiding", this);
+      }
+
+      if (this._button.open) {
+        PanelMultiView.hidePopup(panel);
+        this._button.open = false;
+      } else {
+        panel.hidden = false;
+        PanelMultiView.openPopup(panel, this._button, {
+          triggerEvent: aEvent,
+        });
+      }
+    }
+
+    // We always dispatch an event (useful for testing purposes).
+    window.dispatchEvent(new CustomEvent("UnifiedExtensionsTogglePanel"));
+  },
+
+  async updateContextMenu(menu, event) {
+    // When the context menu is open, `onpopupshowing` is called when menu
+    // items open sub-menus. We don't want to update the context menu in this
+    // case.
+    if (event.target.id !== "unified-extensions-context-menu") {
+      return;
+    }
+
+    const id = this._getExtensionId(menu);
+    const addon = await AddonManager.getAddonByID(id);
+    const widgetId = this._getWidgetId(menu);
+    const forBrowserAction = !!widgetId;
+
+    const pinButton = menu.querySelector(
+      ".unified-extensions-context-menu-pin-to-toolbar"
+    );
+    const removeButton = menu.querySelector(
+      ".unified-extensions-context-menu-remove-extension"
+    );
+    const reportButton = menu.querySelector(
+      ".unified-extensions-context-menu-report-extension"
+    );
+    const menuSeparator = menu.querySelector(
+      ".unified-extensions-context-menu-management-separator"
+    );
+
+    menuSeparator.hidden = !forBrowserAction;
+    pinButton.hidden = !forBrowserAction;
+
+    if (forBrowserAction) {
+      let area = CustomizableUI.getPlacementOfWidget(widgetId).area;
+      let inToolbar = area != CustomizableUI.AREA_ADDONS;
+      pinButton.setAttribute("checked", inToolbar);
+    }
+
+    reportButton.hidden = !gAddonAbuseReportEnabled;
+    removeButton.disabled = !(
+      addon.permissions & AddonManager.PERM_CAN_UNINSTALL
+    );
+
+    ExtensionsUI.originControlsMenu(menu, id);
+
+    const browserAction = this.browserActionFor(WebExtensionPolicy.getByID(id));
+    if (browserAction) {
+      browserAction.updateContextMenu(menu);
+    }
+  },
+
+  // This is registered on the top-level unified extensions context menu.
+  onContextMenuCommand(menu, event) {
+    this.togglePanel();
+  },
+
+  browserActionFor(policy) {
+    // Ideally, we wouldn't do that because `browserActionFor()` will only be
+    // defined in `global` when at least one extension has required loading the
+    // `ext-browserAction` code.
+    let method = lazy.ExtensionParent.apiManager.global.browserActionFor;
+    return method?.(policy?.extension);
+  },
+
+  async manageExtension(menu) {
+    const id = this._getExtensionId(menu);
+
+    await BrowserAddonUI.manageAddon(id, "unifiedExtensions");
+  },
+
+  async removeExtension(menu) {
+    const id = this._getExtensionId(menu);
+
+    await BrowserAddonUI.removeAddon(id, "unifiedExtensions");
+  },
+
+  async reportExtension(menu) {
+    const id = this._getExtensionId(menu);
+
+    await BrowserAddonUI.reportAddon(id, "unified_context_menu");
+  },
+
+  _getExtensionId(menu) {
+    const { triggerNode } = menu;
+    return triggerNode.dataset.extensionid;
+  },
+
+  _getWidgetId(menu) {
+    const { triggerNode } = menu;
+    return triggerNode.closest(".unified-extensions-item")?.id;
+  },
+
+  async onPinToToolbarChange(menu, event) {
+    let shouldPinToToolbar = event.target.getAttribute("checked") == "true";
+    // Revert the checkbox back to its original state. This is because the
+    // addon context menu handlers are asynchronous, and there seems to be
+    // a race where the checkbox state won't get set in time to show the
+    // right state. So we err on the side of caution, and presume that future
+    // attempts to open this context menu on an extension button will show
+    // the same checked state that we started in.
+    event.target.setAttribute("checked", !shouldPinToToolbar);
+
+    let widgetId = this._getWidgetId(menu);
+    if (!widgetId) {
+      return;
+    }
+
+    this.pinToToolbar(widgetId, shouldPinToToolbar);
+  },
+
+  pinToToolbar(widgetId, shouldPinToToolbar) {
+    let newArea = shouldPinToToolbar
+      ? CustomizableUI.AREA_NAVBAR
+      : CustomizableUI.AREA_ADDONS;
+    let newPosition = shouldPinToToolbar ? undefined : 0;
+
+    CustomizableUI.addWidgetToArea(widgetId, newArea, newPosition);
+
+    this.updateAttention();
+  },
+};