v141 Suche nach einem Skript zum Show\Hide Title Bar

 //  titlebar tabs

  (function() {

  if (!window.gBrowser) return;

    const prefs = Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);
    let ProfilePath = PathUtils.toFileURI(PathUtils.join(PathUtils.profileDir, 'chrome', 'icons'));

    try {
        CustomizableUI.createWidget({
            id: 'title_toggle',
            type: 'custom',
            defaultArea: CustomizableUI.AREA_NAVBAR,
            onBuild: function(aDocument) {
                let toolbaritem = aDocument.createXULElement('toolbarbutton');
                let buttonicon = "Letterst-2a.png"
                let props = {
                    id: 'title_toggle',
                    class: 'toolbarbutton-1 chromeclass-toolbar-additional',
                    label: 'Titlebar Tabs',
                    tooltiptext: 'Tabs in Titlebar',
                    style: 'list-style-image: url("' + ProfilePath + buttonicon + '");'
                };
                for (let p in props)
                    toolbaritem.setAttribute(p, props[p]);
                return toolbaritem;
            }
        });
    } catch(e) { }

      document.getElementById('title_toggle').addEventListener('click', event => {
          if (event.button === 0) {
             tabsTitlebar();
            }
    });

    function tabsTitlebar() {
        if (prefs.getIntPref("browser.tabs.inTitlebar") === 0) {
           prefs.setIntPref("browser.tabs.inTitlebar", 1);
        }
        else {
           prefs.setIntPref("browser.tabs.inTitlebar", 0);
        }
     };

  })();

 //  titlebar tabs
 // Pfad im Skript geändert, Zeile 10 + 25
 //https://www.camp-firefox.de/forum/thema/139604-v141-suche-nach-einem-skript-zum-show-hide-title-bar/?postID=1275443#post1275443

  (function() {

  if (!window.gBrowser) return;

    const prefs = Components.classes["@mozilla.org/preferences-service;1"].getService(Components.interfaces.nsIPrefBranch);
    let currentProfileDirectory = Services.dirsvc.get("ProfD", Ci.nsIFile).path.replace(/\\/g, "/");

    try {
        CustomizableUI.createWidget({
            id: 'title_toggle',
            type: 'custom',
            defaultArea: CustomizableUI.AREA_NAVBAR,
            onBuild: function(aDocument) {
                let toolbaritem = aDocument.createXULElement('toolbarbutton');
                let buttonicon = "1.png"
                let props = {
                    id: 'title_toggle',
                    class: 'toolbarbutton-1 chromeclass-toolbar-additional',
                    label: 'Titlebar Tabs',
                    tooltiptext: 'Tabs in Titlebar',
                    style: 'list-style-image: url("' + ("file:" + currentProfileDirectory + "/chrome/icons/" + buttonicon) +'");'
                };
                for (let p in props)
                    toolbaritem.setAttribute(p, props[p]);
                return toolbaritem;
            }
        });
    } catch(e) { }

      document.getElementById('title_toggle').addEventListener('click', event => {
          if (event.button === 0) {
             tabsTitlebar();
            }
    });

    function tabsTitlebar() {
        if (prefs.getIntPref("browser.tabs.inTitlebar") === 0) {
           prefs.setIntPref("browser.tabs.inTitlebar", 1);
        }
        else {
           prefs.setIntPref("browser.tabs.inTitlebar", 0);
        }
     };

  })();