Bug 1909535 - Don't show select dropdown in background tabs; a=dmeehan

  },

  open(browser, menulist, rect, isOpenedViaTouch, selectParentActor) {

    const canOpen = (() => {

      if (!menulist.ownerDocument.hasFocus()) {

        // Don't open in inactive browser windows.

        return false;

      }

      if (browser) {

        if (!browser.browsingContext.isActive) {

          // Don't open in inactive tabs.

          return false;

        }

        let tabbrowser = browser.getTabBrowser();

        if (tabbrowser && tabbrowser.selectedBrowser != browser) {

          // AsyncTabSwitcher might delay activating our browser, check

          // explicitly for tabbrowser.

          return false;

        }

      }

      return true;

    })();

    if (!canOpen) {

      selectParentActor.sendAsyncMessage("Forms:DismissedDropDown", {});

      return;

    }

    this._actor = selectParentActor;

    menulist.hidden = false;

    this._currentBrowser = browser;