--- a/browser/components/touchbar/MacTouchBar.js
+++ b/browser/components/touchbar/MacTouchBar.js
@@ -2,50 +2,35 @@
  * 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/. */
 
 const { XPCOMUtils } = ChromeUtils.import(
   "resource://gre/modules/XPCOMUtils.jsm"
 );
 
 XPCOMUtils.defineLazyModuleGetters(this, {
-  AppConstants: "resource://gre/modules/AppConstants.jsm",
   BrowserWindowTracker: "resource:///modules/BrowserWindowTracker.jsm",
-  PlacesUtils: "resource://gre/modules/PlacesUtils.jsm",
   PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.jsm",
   Services: "resource://gre/modules/Services.jsm",
-  UrlbarTokenizer: "resource:///modules/UrlbarTokenizer.jsm",
+  AppConstants: "resource://gre/modules/AppConstants.jsm",
+  PlacesUtils: "resource://gre/modules/PlacesUtils.jsm",
 });
 
-XPCOMUtils.defineLazyServiceGetter(
-  this,
-  "gTouchBarUpdater",
-  "@mozilla.org/widget/touchbarupdater;1",
-  "nsITouchBarUpdater"
-);
-
-// For accessing TouchBarHelper methods from static contexts in this file.
-XPCOMUtils.defineLazyServiceGetter(
-  this,
-  "gTouchBarHelper",
-  "@mozilla.org/widget/touchbarhelper;1",
-  "nsITouchBarHelper"
-);
-
 /**
  * Executes a XUL command on the top window. Called by the callbacks in each
  * TouchBarInput.
  * @param {string} commandName
  *        A XUL command.
  * @param {string} telemetryKey
  *        A string describing the command, sent for telemetry purposes.
  *        Intended to be shorter and more readable than the XUL command.
  */
 function execCommand(commandName, telemetryKey) {
-  let command = TouchBarHelper.window.document.getElementById(commandName);
+  let win = BrowserWindowTracker.getTopWindow();
+  let command = win.document.getElementById(commandName);
   if (command) {
     command.doCommand();
   }
   let telemetry = Services.telemetry.getHistogramById(
     "TOUCHBAR_BUTTON_PRESSES"
   );
   telemetry.add(telemetryKey);
 }
@@ -62,211 +47,139 @@ function hexToInt(hexString) {
   }
   if (hexString.charAt(0) == "#") {
     hexString = hexString.slice(1);
   }
   let val = parseInt(hexString, 16);
   return isNaN(val) ? null : val;
 }
 
-const kInputTypes = {
-  BUTTON: "button",
-  LABEL: "label",
-  MAIN_BUTTON: "mainButton",
-  POPOVER: "popover",
-  SCROLLVIEW: "scrollView",
-  SCRUBBER: "scrubber",
-};
-
 /**
  * An object containing all implemented TouchBarInput objects.
  */
 const kBuiltInInputs = {
   Back: {
     title: "back",
     image: "chrome://browser/skin/back.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => execCommand("Browser:Back", "Back"),
   },
   Forward: {
     title: "forward",
     image: "chrome://browser/skin/forward.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => execCommand("Browser:Forward", "Forward"),
   },
   Reload: {
     title: "reload",
     image: "chrome://browser/skin/reload.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => execCommand("Browser:Reload", "Reload"),
   },
   Home: {
     title: "home",
     image: "chrome://browser/skin/home.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => {
       let win = BrowserWindowTracker.getTopWindow();
       win.BrowserHome();
       let telemetry = Services.telemetry.getHistogramById(
         "TOUCHBAR_BUTTON_PRESSES"
       );
       telemetry.add("Home");
     },
   },
   Fullscreen: {
     title: "fullscreen",
     image: "chrome://browser/skin/fullscreen.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => execCommand("View:FullScreen", "Fullscreen"),
   },
   Find: {
     title: "find",
     image: "chrome://browser/skin/search-glass.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => execCommand("cmd_find", "Find"),
   },
   NewTab: {
     title: "new-tab",
     image: "chrome://browser/skin/add.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => execCommand("cmd_newNavigatorTabNoEvent", "NewTab"),
   },
   Sidebar: {
     title: "open-sidebar",
     image: "chrome://browser/skin/sidebars.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => {
       let win = BrowserWindowTracker.getTopWindow();
       win.SidebarUI.toggle();
       let telemetry = Services.telemetry.getHistogramById(
         "TOUCHBAR_BUTTON_PRESSES"
       );
       telemetry.add("Sidebar");
     },
   },
   AddBookmark: {
     title: "add-bookmark",
     image: "chrome://browser/skin/bookmark-hollow.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => execCommand("Browser:AddBookmarkAs", "AddBookmark"),
   },
   ReaderView: {
     title: "reader-view",
     image: "chrome://browser/skin/readerMode.svg",
-    type: kInputTypes.BUTTON,
+    type: "button",
     callback: () => execCommand("View:ReaderView", "ReaderView"),
     disabled: true, // Updated when the page is found to be Reader View-able.
   },
   OpenLocation: {
     title: "open-location",
     image: "chrome://browser/skin/search-glass.svg",
-    type: kInputTypes.MAIN_BUTTON,
+    type: "mainButton",
     callback: () => execCommand("Browser:OpenLocation", "OpenLocation"),
   },
-  // This is a special-case `type: kInputTypes.SCRUBBER` element.
+  // This is a special-case `type: "scrubber"` element.
   // Scrubbers are not yet generally implemented.
   // See follow-up bug 1502539.
   Share: {
     title: "share",
+    type: "scrubber",
     image: "chrome://browser/skin/share.svg",
-    type: kInputTypes.SCRUBBER,
     callback: () => execCommand("cmd_share", "Share"),
   },
-  SearchPopover: {
-    title: "search-popover",
-    image: "chrome://browser/skin/search-glass.svg",
-    type: kInputTypes.POPOVER,
-    children: {
-      SearchScrollViewLabel: {
-        title: "search-search-in",
-        type: kInputTypes.LABEL,
-      },
-      SearchScrollView: {
-        key: "search-scrollview",
-        type: kInputTypes.SCROLLVIEW,
-        children: {
-          Bookmarks: {
-            title: "search-bookmarks",
-            type: kInputTypes.BUTTON,
-            callback: () =>
-              gTouchBarHelper.insertRestrictionInUrlbar(
-                UrlbarTokenizer.RESTRICT.BOOKMARK
-              ),
-          },
-          History: {
-            title: "search-history",
-            type: kInputTypes.BUTTON,
-            callback: () =>
-              gTouchBarHelper.insertRestrictionInUrlbar(
-                UrlbarTokenizer.RESTRICT.HISTORY
-              ),
-          },
-          OpenTabs: {
-            title: "search-opentabs",
-            type: kInputTypes.BUTTON,
-            callback: () =>
-              gTouchBarHelper.insertRestrictionInUrlbar(
-                UrlbarTokenizer.RESTRICT.OPENPAGE
-              ),
-          },
-          Tags: {
-            title: "search-tags",
-            type: kInputTypes.BUTTON,
-            callback: () =>
-              gTouchBarHelper.insertRestrictionInUrlbar(
-                UrlbarTokenizer.RESTRICT.TAG
-              ),
-          },
-          Titles: {
-            title: "search-titles",
-            type: kInputTypes.BUTTON,
-            callback: () =>
-              gTouchBarHelper.insertRestrictionInUrlbar(
-                UrlbarTokenizer.RESTRICT.TITLE
-              ),
-          },
-        },
-      },
-    },
-  },
 };
 
 const kHelperObservers = new Set([
   "bookmark-icon-updated",
   "reader-mode-available",
   "touchbar-location-change",
   "quit-application",
   "intl:app-locales-changed",
-  "urlbar-focus",
-  "urlbar-blur",
 ]);
 
 /**
  * JS-implemented TouchBarHelper class.
  * Provides services to the Mac Touch Bar.
  */
 class TouchBarHelper {
   constructor() {
     for (let topic of kHelperObservers) {
       Services.obs.addObserver(this, topic);
     }
-    // We cache our search popover since otherwise it is frequently
-    // created/destroyed for the urlbar-focus/blur events.
-    this._searchPopover = this.getTouchBarInput("SearchPopover");
   }
 
   destructor() {
-    this._searchPopover = null;
     for (let topic of kHelperObservers) {
       Services.obs.removeObserver(this, topic);
     }
   }
 
   get activeTitle() {
-    let tabbrowser = TouchBarHelper.window.ownerGlobal.gBrowser;
+    let tabbrowser = this.window.ownerGlobal.gBrowser;
     let activeTitle;
     if (tabbrowser) {
       activeTitle = tabbrowser.selectedBrowser.contentTitle;
     }
     return activeTitle;
   }
 
   get allItems() {
@@ -283,35 +196,25 @@ class TouchBarHelper {
         continue;
       }
       layoutItems.appendElement(input);
     }
 
     return layoutItems;
   }
 
-  static get window() {
+  get window() {
     return BrowserWindowTracker.getTopWindow();
   }
 
-  get isUrlbarFocused() {
-    return TouchBarHelper.window.gURLBar.focused;
-  }
-
-  static get baseWindow() {
-    return TouchBarHelper.window.docShell.treeOwner.QueryInterface(
-      Ci.nsIBaseWindow
-    );
+  get bookmarkingUI() {
+    return this.window.BookmarkingUI;
   }
 
   getTouchBarInput(inputName) {
-    if (inputName == "SearchPopover" && this._searchPopover) {
-      return this._searchPopover;
-    }
-
     // inputName might be undefined if an input's context() returns undefined.
     if (!inputName || !kBuiltInInputs.hasOwnProperty(inputName)) {
       return null;
     }
 
     // context() may specify that one named input "point" to another.
     if (typeof kBuiltInInputs[inputName].context == "function") {
       inputName = kBuiltInInputs[inputName].context();
@@ -319,129 +222,95 @@ class TouchBarHelper {
 
     if (!inputName || !kBuiltInInputs.hasOwnProperty(inputName)) {
       return null;
     }
 
     let inputData = kBuiltInInputs[inputName];
 
     let item = new TouchBarInput(inputData);
-
-    // Skip localization if there is already a cached localized title or if
-    // no title is needed.
-    if (
-      kBuiltInInputs[inputName].hasOwnProperty("localTitle") ||
-      !kBuiltInInputs[inputName].hasOwnProperty("title")
-    ) {
+    // Skip localization if there is already a cached localized title.
+    if (kBuiltInInputs[inputName].hasOwnProperty("localTitle")) {
       return item;
     }
 
     // Async l10n fills in the localized input labels after the initial load.
     this._l10n.formatValue(item.key).then(result => {
       item.title = result;
       kBuiltInInputs[inputName].localTitle = result; // Cache result.
-      // Checking TouchBarHelper.window since this callback can fire after all windows are closed.
-      if (TouchBarHelper.window) {
-        gTouchBarUpdater.updateTouchBarInputs(TouchBarHelper.baseWindow, [
-          item,
-        ]);
+      // Checking this.window since this callback can fire after all windows are closed.
+      if (this.window) {
+        let baseWindow = this.window.docShell.treeOwner.QueryInterface(
+          Ci.nsIBaseWindow
+        );
+        let updater = Cc["@mozilla.org/widget/touchbarupdater;1"].getService(
+          Ci.nsITouchBarUpdater
+        );
+        updater.updateTouchBarInputs(baseWindow, [item]);
       }
     });
 
     return item;
   }
 
   /**
    * Fetches a specific Touch Bar Input by name and updates it on the Touch Bar.
    * @param {string} inputName
    *        A key to a value in the kBuiltInInputs object in this file.
    * @param {...*} [otherInputs] (optional)
    *        Additional keys to values in the kBuiltInInputs object in this file.
    */
   _updateTouchBarInputs(...inputNames) {
-    if (!TouchBarHelper.window) {
+    if (!this.window) {
       return;
     }
 
     let inputs = [];
     for (let inputName of inputNames) {
       let input = this.getTouchBarInput(inputName);
       if (!input) {
         continue;
       }
       inputs.push(input);
     }
 
-    gTouchBarUpdater.updateTouchBarInputs(TouchBarHelper.baseWindow, inputs);
-  }
-
-  /**
-   * Inserts a restriction token into the Urlbar ahead of the current typed
-   * search term.
-   * @param {string} restrictionToken
-   *        The restriction token to be inserted into the Urlbar. Preferably
-   *        sourced from UrlbarTokenizer.RESTRICT.
-   */
-  insertRestrictionInUrlbar(restrictionToken) {
-    let searchString = TouchBarHelper.window.gURLBar.lastSearchString.trimStart();
-    if (Object.values(UrlbarTokenizer.RESTRICT).includes(searchString[0])) {
-      searchString = searchString.substring(1).trimStart();
-    }
-
-    TouchBarHelper.window.gURLBar.search(`${restrictionToken} ${searchString}`);
+    let baseWindow = this.window.docShell.treeOwner.QueryInterface(
+      Ci.nsIBaseWindow
+    );
+    let updater = Cc["@mozilla.org/widget/touchbarupdater;1"].getService(
+      Ci.nsITouchBarUpdater
+    );
+    updater.updateTouchBarInputs(baseWindow, inputs);
   }
 
   observe(subject, topic, data) {
     switch (topic) {
       case "touchbar-location-change":
         this.activeUrl = data;
         // ReaderView button is disabled on every location change since
         // Reader View must determine if the new page can be Reader Viewed.
         kBuiltInInputs.ReaderView.disabled = !data.startsWith("about:reader");
-        kBuiltInInputs.Back.disabled = !TouchBarHelper.window.gBrowser
-          .canGoBack;
-        kBuiltInInputs.Forward.disabled = !TouchBarHelper.window.gBrowser
-          .canGoForward;
+        kBuiltInInputs.Back.disabled = !this.window.gBrowser.canGoBack;
+        kBuiltInInputs.Forward.disabled = !this.window.gBrowser.canGoForward;
         this._updateTouchBarInputs("ReaderView", "Back", "Forward");
         break;
       case "bookmark-icon-updated":
         data == "starred"
           ? (kBuiltInInputs.AddBookmark.image =
               "chrome://browser/skin/bookmark.svg")
           : (kBuiltInInputs.AddBookmark.image =
               "chrome://browser/skin/bookmark-hollow.svg");
         this._updateTouchBarInputs("AddBookmark");
         break;
       case "reader-mode-available":
         kBuiltInInputs.ReaderView.disabled = false;
         this._updateTouchBarInputs("ReaderView");
         break;
-      case "urlbar-focus":
-        if (!this._searchPopover) {
-          this._searchPopover = this.getTouchBarInput("SearchPopover");
-        }
-        gTouchBarUpdater.showPopover(
-          TouchBarHelper.baseWindow,
-          this._searchPopover,
-          true
-        );
-        break;
-      case "urlbar-blur":
-        if (!this._searchPopover) {
-          this._searchPopover = this.getTouchBarInput("SearchPopover");
-        }
-        gTouchBarUpdater.showPopover(
-          TouchBarHelper.baseWindow,
-          this._searchPopover,
-          false
-        );
-        break;
       case "intl:app-locales-changed":
         // On locale change, refresh all inputs after loading new localTitle.
-        this._searchPopover = null;
         for (let input in kBuiltInInputs) {
           delete input.localTitle;
         }
         this._updateTouchBarInputs(...kBuiltInInputs.keys());
         break;
       case "quit-application":
         this.destructor();
         break;
@@ -453,82 +322,58 @@ const helperProto = TouchBarHelper.proto
 helperProto.classDescription = "Services the Mac Touch Bar";
 helperProto.classID = Components.ID("{ea109912-3acc-48de-b679-c23b6a122da5}");
 helperProto.contractID = "@mozilla.org/widget/touchbarhelper;1";
 helperProto.QueryInterface = ChromeUtils.generateQI([Ci.nsITouchBarHelper]);
 helperProto._l10n = new Localization(["browser/touchbar/touchbar.ftl"]);
 
 /**
  * A representation of a Touch Bar input.
+ * Uses async update() in lieu of a constructor to accomodate async l10n code.
  *     @param {object} input
  *            An object representing a Touch Bar Input.
  *            Contains listed properties.
  *     @param {string} input.title
  *            The lookup key for the button's localized text title.
  *     @param {string} input.image
  *            The name of a icon file added to
  *            /widget/cocoa/resources/touchbar_icons.
  *     @param {string} input.type
  *            The type of Touch Bar input represented by the object.
  *            One of `button`, `mainButton`.
  *     @param {Function} input.callback
  *            A callback invoked when a touchbar item is touched.
- *     @param {string} [input.color]
+ *     @param {string} input.color (optional)
  *            A string in hex format specifying the button's background color.
  *            If omitted, the default background color is used.
- *     @param {bool} [input.disabled]
+ *     @param {bool} input.disabled (optional)
  *            If `true`, the Touch Bar input is greyed out and inoperable.
- *     @param {Array} [input.children]
- *            An array of input objects that will be displayed as children of
- *            this input. Available only for types KInputTypes.POPOVER and
- *            kInputTypes.SCROLLVIEW.
  */
 class TouchBarInput {
   constructor(input) {
-    this._key = input.key || input.title;
+    this._key = input.title;
     this._title = input.hasOwnProperty("localTitle") ? input.localTitle : "";
     this._image = input.image;
     this._type = input.type;
     this._callback = input.callback;
     this._color = hexToInt(input.color);
     this._disabled = input.hasOwnProperty("disabled") ? input.disabled : false;
-    if (input.children) {
-      this._children = [];
-      let toLocalize = [];
-      for (let childData of Object.values(input.children)) {
-        let initializedChild = new TouchBarInput(childData);
-        if (!initializedChild) {
-          continue;
-        }
-        // Children's types are prepended by the parent's type. This is so we
-        // can uniquely identify a child input from a standalone input with
-        // the same name. (e.g. a button called "back" in a popover would be a
-        // "popover-button.back" vs. a "button.back").
-        initializedChild.type = input.type + "-" + initializedChild.type;
-        this._children.push(initializedChild);
-        // Skip l10n for inputs without a title or those already localized.
-        if (childData.title && childData.title != "") {
-          toLocalize.push(initializedChild);
-        }
-      }
-      this._localizeChildren(toLocalize);
-    }
   }
 
   get key() {
     return this._key;
   }
   get title() {
     return this._title;
   }
   set title(title) {
     this._title = title;
   }
   get image() {
-    return this._image ? PlacesUtils.toURI(this._image) : null;
+    return PlacesUtils.toURI(this._image);
   }
   set image(image) {
     this._image = image;
   }
   // Required as context to load our input icons.
   get document() {
     return BrowserWindowTracker.getTopWindow().document;
   }
@@ -551,45 +396,16 @@ class TouchBarInput {
     this._color = this.hexToInt(color);
   }
   get disabled() {
     return this._disabled || false;
   }
   set disabled(disabled) {
     this._disabled = disabled;
   }
-  get children() {
-    if (!this._children) {
-      return null;
-    }
-    let children = Cc["@mozilla.org/array;1"].createInstance(
-      Ci.nsIMutableArray
-    );
-    for (let child of this._children) {
-      children.appendElement(child);
-    }
-    return children;
-  }
-
-  /**
-   * Apply Fluent l10n to child inputs.
-   * @param {Array} children An array of initialized TouchBarInputs.
-   */
-  async _localizeChildren(children) {
-    let titles = await helperProto._l10n.formatValues(
-      children.map(child => ({ id: child.key }))
-    );
-    // In the TouchBarInput constuctor, we filtered so children contains only
-    // those inputs with titles to be localized. We can be confident that the
-    // results in titles match up with the inputs to be localized.
-    children.forEach(function(child, index) {
-      child.title = titles[index];
-    });
-    gTouchBarUpdater.updateTouchBarInputs(TouchBarHelper.baseWindow, children);
-  }
 }
 
 const inputProto = TouchBarInput.prototype;
 inputProto.classDescription = "Represents an input on the Mac Touch Bar";
 inputProto.classID = Components.ID("{77441d17-f29c-49d7-982f-f20a5ab5a900}");
 inputProto.contractID = "@mozilla.org/widget/touchbarinput;1";
 inputProto.QueryInterface = ChromeUtils.generateQI([Ci.nsITouchBarInput]);
 

--- a/browser/components/touchbar/tests/browser/browser.ini
+++ b/browser/components/touchbar/tests/browser/browser.ini
@@ -1,6 +1,5 @@
 [DEFAULT]
 support-files =
   readerModeArticle.html
 
-[browser_touchbar_searchrestrictions.js]
-[browser_touchbar_tests.js]
+[browser_touchbar_tests.js]
\ No newline at end of file

deleted file mode 100644
--- a/browser/components/touchbar/tests/browser/browser_touchbar_searchrestrictions.js
+++ /dev/null
@@ -1,129 +0,0 @@
-/* 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/. */
-
-const { XPCOMUtils } = ChromeUtils.import(
-  "resource://gre/modules/XPCOMUtils.jsm"
-);
-
-XPCOMUtils.defineLazyModuleGetters(this, {
-  UrlbarTokenizer: "resource:///modules/UrlbarTokenizer.jsm",
-});
-
-XPCOMUtils.defineLazyServiceGetter(
-  this,
-  "TouchBarHelper",
-  "@mozilla.org/widget/touchbarhelper;1",
-  "nsITouchBarHelper"
-);
-
-add_task(async function insertTokens() {
-  const tests = [
-    {
-      input: "",
-      token: UrlbarTokenizer.RESTRICT.HISTORY,
-      expected: "^ ",
-    },
-    {
-      input: "mozilla",
-      token: UrlbarTokenizer.RESTRICT.HISTORY,
-      expected: "^ mozilla",
-    },
-    {
-      input: "mozilla",
-      token: UrlbarTokenizer.RESTRICT.BOOKMARK,
-      expected: "* mozilla",
-    },
-    {
-      input: "mozilla",
-      token: UrlbarTokenizer.RESTRICT.TAG,
-      expected: "+ mozilla",
-    },
-    {
-      input: "mozilla",
-      token: UrlbarTokenizer.RESTRICT.OPENPAGE,
-      expected: "% mozilla",
-    },
-    {
-      input: "mozilla",
-      token: UrlbarTokenizer.RESTRICT.TITLE,
-      expected: "# mozilla",
-    },
-  ];
-  let win = BrowserWindowTracker.getTopWindow();
-  for (let { input, token, expected } of tests) {
-    win.gURLBar.search(input);
-    TouchBarHelper.insertRestrictionInUrlbar(token);
-    Assert.equal(
-      win.gURLBar.value,
-      expected,
-      "The search restriction token should have been entered."
-    );
-  }
-});
-
-add_task(async function existingTokens() {
-  const tests = [
-    {
-      input: "* mozilla",
-      token: UrlbarTokenizer.RESTRICT.HISTORY,
-      expected: "^ mozilla",
-    },
-    {
-      input: "+ mozilla",
-      token: UrlbarTokenizer.RESTRICT.BOOKMARK,
-      expected: "* mozilla",
-    },
-    {
-      input: "( $ ^ mozilla",
-      token: UrlbarTokenizer.RESTRICT.TAG,
-      expected: "+ ( $ ^ mozilla",
-    },
-    {
-      input: "^*+%?#$ mozilla",
-      token: UrlbarTokenizer.RESTRICT.TAG,
-      expected: "+ *+%?#$ mozilla",
-    },
-  ];
-  let win = BrowserWindowTracker.getTopWindow();
-  for (let { input, token, expected } of tests) {
-    win.gURLBar.search(input);
-    TouchBarHelper.insertRestrictionInUrlbar(token);
-    Assert.equal(
-      win.gURLBar.value,
-      expected,
-      "The search restriction token should have been replaced."
-    );
-  }
-});
-
-add_task(async function stripSpaces() {
-  const tests = [
-    {
-      input: "     ^     mozilla",
-      token: UrlbarTokenizer.RESTRICT.HISTORY,
-      expected: "^ mozilla",
-    },
-    {
-      input: "     +         mozilla   ",
-      token: UrlbarTokenizer.RESTRICT.BOOKMARK,
-      expected: "* mozilla   ",
-    },
-    {
-      input: "  moz    illa  ",
-      token: UrlbarTokenizer.RESTRICT.TAG,
-      expected: "+ moz    illa  ",
-    },
-  ];
-  let win = BrowserWindowTracker.getTopWindow();
-  for (let { input, token, expected } of tests) {
-    win.gURLBar.search(input);
-    TouchBarHelper.insertRestrictionInUrlbar(token);
-    Assert.equal(
-      win.gURLBar.value,
-      expected,
-      "The search restriction token should have been entered " +
-        "with stripped whitespace."
-    );
-  }
-});

--- a/browser/components/urlbar/UrlbarInput.jsm
+++ b/browser/components/urlbar/UrlbarInput.jsm
@@ -978,24 +978,16 @@ class UrlbarInput {
   get untrimmedValue() {
     return this._untrimmedValue;
   }
 
   set value(val) {
     return this._setValue(val, true);
   }
 
-  get lastSearchString() {
-    return this._lastSearchString;
-  }
-
-  get openViewOnFocus() {
-    return this._openViewOnFocus;
-  }
-
   get openViewOnFocusForCurrentTab() {
     return (
       this._openViewOnFocusAndSearchString ||
       (this._openViewOnFocus &&
         !["about:newtab", "about:home"].includes(
           this.window.gBrowser.currentURI.spec
         ) &&
         !this.isPrivate)
@@ -1777,18 +1769,16 @@ class UrlbarInput {
     if (!UrlbarPrefs.get("ui.popup.disable_autohide")) {
       this.view.close();
     }
 
     // We may have hidden popup notifications, show them again if necessary.
     if (this.getAttribute("pageproxystate") != "valid") {
       this.window.UpdatePopupNotificationsVisibility();
     }
-
-    Services.obs.notifyObservers(null, "urlbar-blur");
   }
 
   _on_click(event) {
     if (
       event.target == this.inputField ||
       event.target == this._inputContainer
     ) {
       this.startLayoutExtend();
@@ -1819,18 +1809,16 @@ class UrlbarInput {
 
     this._updateUrlTooltip();
     this.formatValue();
 
     // Hide popup notifications, to reduce visual noise.
     if (this.getAttribute("pageproxystate") != "valid") {
       this.window.UpdatePopupNotificationsVisibility();
     }
-
-    Services.obs.notifyObservers(null, "urlbar-focus");
   }
 
   _on_mouseover(event) {
     this._updateUrlTooltip();
   }
 
   _on_mousedown(event) {
     switch (event.currentTarget) {

--- a/browser/locales/en-US/browser/touchbar/touchbar.ftl
+++ b/browser/locales/en-US/browser/touchbar/touchbar.ftl
@@ -13,22 +13,8 @@ find = Find
 new-tab = New tab
 add-bookmark = Add bookmark
 reader-view = Reader View
 # Meant to match the string displayed in an empty URL bar.
 open-location = Search or enter address
 share = Share
 close-window = Close Window
 open-sidebar = Sidebars
-
-# This string describes shortcuts for search.
-search-popover = Search shortcuts
-# Describes searches limited to a specific scope
-# (e.g. searching only in history).
-search-search-in = Search in:
-## Various categories of shortcuts for search.
-
-search-bookmarks = Bookmarks
-search-history = History
-search-opentabs = Open Tabs
-search-tags = Tags
-search-titles = Titles
-##

--- a/toolkit/library/moz.build
+++ b/toolkit/library/moz.build
@@ -69,17 +69,16 @@ def Libxul(name, output_category=None):
     # We need to weak link these classes until we've upgraded our SDK to at
     # least 10.12.2.
     # We're also linking against libresolv to solve bug 1367932.
     if CONFIG['OS_ARCH'] == 'Darwin':
         LDFLAGS += ['-Wl,-U,_OBJC_CLASS_$_NSTouchBar']
         LDFLAGS += ['-Wl,-U,_OBJC_CLASS_$_NSSharingServicePickerTouchBarItem']
         LDFLAGS += ['-Wl,-U,_OBJC_METACLASS_$_NSTouchBar']
         LDFLAGS += ['-Wl,-U,_OBJC_CLASS_$_NSCustomTouchBarItem']
-        LDFLAGS += ['-Wl,-U,_OBJC_CLASS_$_NSPopoverTouchBarItem']
         LDFLAGS += ['-lresolv']
 
     if CONFIG['MOZ_DEBUG_SYMBOLS'] and CONFIG['CC_TYPE'] == 'clang-cl':
         LDFLAGS += ['-NATVIS:%s/toolkit/library/gecko.natvis' % TOPSRCDIR]
     if CONFIG['RUSTC_NATVIS_LDFLAGS']:
         LDFLAGS += CONFIG['RUSTC_NATVIS_LDFLAGS']
 
     if CONFIG['OS_ARCH'] == 'Linux' and CONFIG['OS_TARGET'] != 'Android':

--- a/widget/cocoa/nsTouchBar.h
+++ b/widget/cocoa/nsTouchBar.h
@@ -20,69 +20,58 @@ using namespace mozilla::dom;
 @interface TouchBarInput : NSObject {
   NSString* mKey;
   NSString* mTitle;
   nsCOMPtr<nsIURI> mImageURI;
   RefPtr<nsTouchBarInputIcon> mIcon;
   NSString* mType;
   NSColor* mColor;
   BOOL mDisabled;
+  NSTouchBarItemIdentifier mNativeIdentifier;
   nsCOMPtr<nsITouchBarInputCallback> mCallback;
   RefPtr<Document> mDocument;
   BOOL mIsIconPositionSet;
-  NSMutableArray<TouchBarInput*>* mChildren;
 }
 
 - (NSString*)key;
 - (NSString*)title;
 - (nsCOMPtr<nsIURI>)imageURI;
 - (RefPtr<nsTouchBarInputIcon>)icon;
 - (NSString*)type;
 - (NSColor*)color;
 - (BOOL)isDisabled;
 - (NSTouchBarItemIdentifier)nativeIdentifier;
 - (nsCOMPtr<nsITouchBarInputCallback>)callback;
 - (RefPtr<Document>)document;
 - (BOOL)isIconPositionSet;
-- (NSMutableArray<TouchBarInput*>*)children;
 - (void)setKey:(NSString*)aKey;
 - (void)setTitle:(NSString*)aTitle;
 - (void)setImageURI:(nsCOMPtr<nsIURI>)aImageURI;
 - (void)setIcon:(RefPtr<nsTouchBarInputIcon>)aIcon;
 - (void)setType:(NSString*)aType;
 - (void)setColor:(NSColor*)aColor;
 - (void)setDisabled:(BOOL)aDisabled;
+- (void)setNativeIdentifier:(NSString*)aNativeIdentifier;
 - (void)setCallback:(nsCOMPtr<nsITouchBarInputCallback>)aCallback;
 - (void)setDocument:(RefPtr<Document>)aDocument;
 - (void)setIconPositionSet:(BOOL)aIsIconPositionSet;
-- (void)setChildren:(NSMutableArray<TouchBarInput*>*)aChildren;
 
 - (id)initWithKey:(NSString*)aKey
             title:(NSString*)aTitle
          imageURI:(nsCOMPtr<nsIURI>)aImageURI
              type:(NSString*)aType
          callback:(nsCOMPtr<nsITouchBarInputCallback>)aCallback
             color:(uint32_t)aColor
          disabled:(BOOL)aDisabled
-         document:(RefPtr<Document>)aDocument
-         children:(nsCOMPtr<nsIArray>)aChildren;
+         document:(RefPtr<Document>)aDocument;
 
 - (TouchBarInput*)initWithXPCOM:(nsCOMPtr<nsITouchBarInput>)aInput;
 
-- (void)releaseJSObjects;
-
 - (void)dealloc;
 
-/**
- * We make this helper method static so that other classes can query a
- * TouchBarInput's nativeIdentifier (e.g. nsTouchBarUpdater looking up a
- * popover in mappedLayoutItems).
- */
-+ (NSTouchBarItemIdentifier)nativeIdentifierWithType:(NSString*)aType withKey:(NSString*)aKey;
-
 @end
 
 /**
  * Our TouchBar is its own delegate. This is adequate for our purposes,
  * since the current implementation only defines Touch Bar buttons for the
  * main Firefox window. If modals and other windows were to have custom
  * Touch Bar views, each window would have to be a NSTouchBarDelegate so
  * they could define their own custom sets of buttons.
@@ -99,88 +88,47 @@ using namespace mozilla::dom;
 
 /**
  * Contains TouchBarInput representations of the inputs currently in
  * the Touch Bar. Populated in `init` and updated by nsITouchBarUpdater.
  */
 @property(strong) NSMutableDictionary<NSTouchBarItemIdentifier, TouchBarInput*>* mappedLayoutItems;
 
 /**
- * Stores buttons displayed in a NSScrollView. They must be stored separately
- * because they are generic NSButtons and not NSTouchBarItems. As such, they
- * cannot be retrieved with [NSTouchBar itemForIdentifier].
- */
-@property(strong) NSMutableDictionary<NSTouchBarItemIdentifier, NSButton*>* scrollViewButtons;
-
-/**
  * Returns an instance of nsTouchBar based on implementation details
  * fetched from the frontend through nsTouchBarHelper.
  */
 - (instancetype)init;
 
-/**
- * If aInputs is not nil, a nsTouchBar containing the inputs specified is
- * initialized. Otherwise, a nsTouchBar is initialized containing a default set
- * of inputs.
- */
-- (instancetype)initWithInputs:(NSMutableArray<TouchBarInput*>*)aInputs;
-
 - (void)dealloc;
 
 /**
  * Creates a new NSTouchBarItem and adds it to the Touch Bar.
  * Reads the passed identifier and creates the
  * appropriate item type (eg. NSCustomTouchBarItem).
  * Required as a member of NSTouchBarDelegate.
  */
 - (NSTouchBarItem*)touchBar:(NSTouchBar*)aTouchBar
       makeItemForIdentifier:(NSTouchBarItemIdentifier)aIdentifier;
 
 /**
  * Updates an input on the Touch Bar by redirecting to one of the specific
  * TouchBarItem types updaters.
- * Returns true if the input was successfully updated.
  */
-- (bool)updateItem:(TouchBarInput*)aInput;
-
-/**
- * Helper function for updateItem. Checks to see if a given input exists within
- * any of this Touch Bar's popovers and updates it if it exists.
- */
-- (bool)maybeUpdatePopoverChild:(TouchBarInput*)aInput;
-
-/**
- * Helper function for updateItem. Checks to see if a given input exists within
- * any of this Touch Bar's scroll views and updates it if it exists.
- */
-- (bool)maybeUpdateScrollViewChild:(TouchBarInput*)aInput;
-
-/**
- * Helper function for updateItem. Replaces an item in the
- * self.mappedLayoutItems dictionary.
- */
-- (void)replaceMappedLayoutItem:(TouchBarInput*)aItem;
+- (void)updateItem:(TouchBarInput*)aInput;
 
 /**
  * Update or create various subclasses of TouchBarItem.
  */
-- (void)updateButton:(NSButton*)aButton input:(TouchBarInput*)aInput;
-- (void)updateMainButton:(NSButton*)aMainButton input:(TouchBarInput*)aInput;
-- (void)updatePopover:(NSPopoverTouchBarItem*)aPopoverItem input:(TouchBarInput*)aInput;
-- (void)updateScrollView:(NSCustomTouchBarItem*)aScrollViewItem input:(TouchBarInput*)aInput;
-- (void)updateLabel:(NSTextField*)aLabel input:(TouchBarInput*)aInput;
+- (NSTouchBarItem*)updateButton:(NSCustomTouchBarItem*)aButton input:(TouchBarInput*)aInput;
+- (NSTouchBarItem*)updateMainButton:(NSCustomTouchBarItem*)aMainButton input:(TouchBarInput*)aInput;
 - (NSTouchBarItem*)makeShareScrubberForIdentifier:(NSTouchBarItemIdentifier)aIdentifier;
 
 /**
- * If aShowing is true, aPopover is shown. Otherwise, it is hidden.
- */
-- (void)showPopover:(TouchBarInput*)aPopover showing:(bool)aShowing;
-
-/**
- *  Redirects button actions to the appropriate handler.
+ *  Redirects button actions to the appropriate handler and handles telemetry.
  */
 - (void)touchBarAction:(id)aSender;
 
 - (NSArray*)itemsForSharingServicePickerTouchBarItem:
     (NSSharingServicePickerTouchBarItem*)aPickerTouchBarItem;
 
 - (NSArray<NSSharingService*>*)sharingServicePicker:(NSSharingServicePicker*)aSharingServicePicker
                             sharingServicesForItems:(NSArray*)aItems

--- a/widget/cocoa/nsTouchBar.mm
+++ b/widget/cocoa/nsTouchBar.mm
@@ -7,420 +7,190 @@
 #include "mozilla/MacStringHelpers.h"
 #include "mozilla/Telemetry.h"
 #include "nsArrayUtils.h"
 #include "nsDirectoryServiceDefs.h"
 #include "nsIArray.h"
 
 @implementation nsTouchBar
 
-static const NSTouchBarItemIdentifier BaseIdentifier = @"com.mozilla.firefox.touchbar";
+static NSTouchBarItemIdentifier CustomButtonIdentifier = @"com.mozilla.firefox.touchbar.button";
+static NSTouchBarItemIdentifier CustomMainButtonIdentifier =
+    @"com.mozilla.firefox.touchbar.mainbutton";
+static NSTouchBarItemIdentifier ScrubberIdentifier = @"com.mozilla.firefox.touchbar.scrubber";
 
 // Non-JS scrubber implemention for the Share Scrubber,
 // since it is defined by an Apple API.
 static NSTouchBarItemIdentifier ShareScrubberIdentifier =
-    [TouchBarInput nativeIdentifierWithType:@"scrubber" withKey:@"share"];
-
-// The search popover needs to show/hide depending on if the Urlbar is focused
-// when it is created. We keep track of its identifier to accomodate this
-// special handling.
-static NSTouchBarItemIdentifier SearchPopoverIdentifier =
-    [TouchBarInput nativeIdentifierWithType:@"popover" withKey:@"search-popover"];
+    [ScrubberIdentifier stringByAppendingPathExtension:@"share"];
 
 // Used to tie action strings to buttons.
 static char sIdentifierAssociationKey;
 
-static const NSArray<NSString*>* kAllowedInputTypes = @[
-  @"button",
-  @"mainButton",
-  @"scrubber",
-  @"popover",
-  @"scrollView",
-  @"label",
-];
-
-// The default space between inputs, used where layout is not automatic.
-static const uint32_t kInputSpacing = 8;
-// The width of buttons in Apple's Share ScrollView. We use this in our
-// ScrollViews to give them a native appearance.
-static const uint32_t kScrollViewButtonWidth = 144;
-static const uint32_t kInputIconSize = 16;
-
 // The system default width for Touch Bar inputs is 128px. This is double.
 #define MAIN_BUTTON_WIDTH 256
 
 #pragma mark - NSTouchBarDelegate
 
 - (instancetype)init {
-  return [self initWithInputs:nil];
-}
-
-- (instancetype)initWithInputs:(NSMutableArray<TouchBarInput*>*)aInputs {
   if ((self = [super init])) {
     mTouchBarHelper = do_GetService(NS_TOUCHBARHELPER_CID);
     if (!mTouchBarHelper) {
-      NS_ERROR("Unable to create Touch Bar Helper.");
       return nil;
     }
 
     self.delegate = self;
+    // This customization identifier is how users' custom layouts are saved by macOS.
+    // If this changes, all users' layouts would be reset to the default layout.
+    self.customizationIdentifier = @"com.mozilla.firefox.touchbar.defaultbar";
     self.mappedLayoutItems = [NSMutableDictionary dictionary];
-    self.customizationAllowedItemIdentifiers = nil;
+    nsCOMPtr<nsIArray> allItems;
+
+    nsresult rv = mTouchBarHelper->GetAllItems(getter_AddRefs(allItems));
+    if (NS_FAILED(rv) || !allItems) {
+      return nil;
+    }
 
-    if (!aInputs) {
-      // This customization identifier is how users' custom layouts are saved by macOS.
-      // If this changes, all users' layouts would be reset to the default layout.
-      self.customizationIdentifier = [BaseIdentifier stringByAppendingPathExtension:@"defaultbar"];
-      nsCOMPtr<nsIArray> allItems;
-
-      nsresult rv = mTouchBarHelper->GetAllItems(getter_AddRefs(allItems));
-      if (NS_FAILED(rv) || !allItems) {
-        return nil;
+    uint32_t itemCount = 0;
+    allItems->GetLength(&itemCount);
+    // This is copied to self.customizationAllowedItemIdentifiers. Required since
+    // [self.mappedItems allKeys] does not preserve order.
+    // One slot is added for the spacer item.
+    NSMutableArray* orderedIdentifiers = [NSMutableArray arrayWithCapacity:itemCount + 1];
+    for (uint32_t i = 0; i < itemCount; ++i) {
+      nsCOMPtr<nsITouchBarInput> input = do_QueryElementAt(allItems, i);
+      if (!input) {
+        continue;
       }
 
-      uint32_t itemCount = 0;
-      allItems->GetLength(&itemCount);
-      // This is copied to self.customizationAllowedItemIdentifiers.
-      // Required since [self.mappedItems allKeys] does not preserve order.
-      // One slot is added for the spacer item.
-      NSMutableArray* orderedIdentifiers = [NSMutableArray arrayWithCapacity:itemCount + 1];
-      for (uint32_t i = 0; i < itemCount; ++i) {
-        nsCOMPtr<nsITouchBarInput> input = do_QueryElementAt(allItems, i);
-        if (!input) {
-          continue;
-        }
+      TouchBarInput* convertedInput = [[TouchBarInput alloc] initWithXPCOM:input];
 
-        TouchBarInput* convertedInput = [[TouchBarInput alloc] initWithXPCOM:input];
+      // Add new input to dictionary for lookup of properties in delegate.
+      self.mappedLayoutItems[[convertedInput nativeIdentifier]] = convertedInput;
+      orderedIdentifiers[i] = [convertedInput nativeIdentifier];
+    }
+    [orderedIdentifiers addObject:@"NSTouchBarItemIdentifierFlexibleSpace"];
 
-        // Add new input to dictionary for lookup of properties in delegate.
-        self.mappedLayoutItems[[convertedInput nativeIdentifier]] = convertedInput;
-        orderedIdentifiers[i] = [convertedInput nativeIdentifier];
-      }
-      [orderedIdentifiers addObject:@"NSTouchBarItemIdentifierFlexibleSpace"];
-      self.customizationAllowedItemIdentifiers = [orderedIdentifiers copy];
-
-      NSArray* defaultItemIdentifiers = @[
-        [TouchBarInput nativeIdentifierWithType:@"button" withKey:@"back"],
-        [TouchBarInput nativeIdentifierWithType:@"button" withKey:@"forward"],
-        [TouchBarInput nativeIdentifierWithType:@"button" withKey:@"reload"],
-        [TouchBarInput nativeIdentifierWithType:@"mainButton" withKey:@"open-location"],
-        [TouchBarInput nativeIdentifierWithType:@"button" withKey:@"new-tab"],
-        ShareScrubberIdentifier, SearchPopoverIdentifier
-      ];
-      self.defaultItemIdentifiers = [defaultItemIdentifiers copy];
-    } else {
-      NSMutableArray* defaultItemIdentifiers = [NSMutableArray arrayWithCapacity:[aInputs count]];
-      for (TouchBarInput* input in aInputs) {
-        self.mappedLayoutItems[[input nativeIdentifier]] = input;
-        [defaultItemIdentifiers addObject:[input nativeIdentifier]];
-      }
-      self.defaultItemIdentifiers = [defaultItemIdentifiers copy];
-    }
+    NSArray* defaultItemIdentifiers = @[
+      [CustomButtonIdentifier stringByAppendingPathExtension:@"back"],
+      [CustomButtonIdentifier stringByAppendingPathExtension:@"forward"],
+      [CustomButtonIdentifier stringByAppendingPathExtension:@"reload"],
+      [CustomMainButtonIdentifier stringByAppendingPathExtension:@"open-location"],
+      [CustomButtonIdentifier stringByAppendingPathExtension:@"new-tab"], ShareScrubberIdentifier
+    ];
+    self.defaultItemIdentifiers = [defaultItemIdentifiers copy];
+    self.customizationAllowedItemIdentifiers = [orderedIdentifiers copy];
   }
 
   return self;
 }
 
 - (void)dealloc {
   for (NSTouchBarItemIdentifier identifier in self.mappedLayoutItems) {
     NSTouchBarItem* item = [self itemForIdentifier:identifier];
-    if (!item) {
-      continue;
-    }
-    if ([item isKindOfClass:[NSPopoverTouchBarItem class]]) {
-      [(NSPopoverTouchBarItem*)item setCollapsedRepresentation:nil];
-      [(NSPopoverTouchBarItem*)item setCollapsedRepresentationImage:nil];
-      [(nsTouchBar*)[(NSPopoverTouchBarItem*)item popoverTouchBar] release];
-    } else if ([[item view] isKindOfClass:[NSScrollView class]]) {
-      [[(NSScrollView*)[item view] documentView] release];
-    }
-
-    [[item view] release];
     [item release];
   }
 
   [self.defaultItemIdentifiers release];
   [self.customizationAllowedItemIdentifiers release];
-  [self.scrollViewButtons removeAllObjects];
-  [self.scrollViewButtons release];
   [self.mappedLayoutItems removeAllObjects];
   [self.mappedLayoutItems release];
   [super dealloc];
 }
 
 - (NSTouchBarItem*)touchBar:(NSTouchBar*)aTouchBar
       makeItemForIdentifier:(NSTouchBarItemIdentifier)aIdentifier {
-  TouchBarInput* input = self.mappedLayoutItems[aIdentifier];
-
-  if (!input) {
-    return nil;
-  }
-
-  // Checking to see if our new item is of an accepted type.
-  if (![kAllowedInputTypes
-          containsObject:[[[input type] componentsSeparatedByString:@"-"] lastObject]]) {
-    return nil;
-  }
-
-  if ([[input type] hasSuffix:@"scrubber"]) {
-    // We check the identifier rather than the type here as a special case.
+  if ([aIdentifier hasPrefix:ScrubberIdentifier]) {
     if (![aIdentifier isEqualToString:ShareScrubberIdentifier]) {
       // We're only supporting the Share scrubber for now.
       return nil;
     }
     return [self makeShareScrubberForIdentifier:aIdentifier];
   }
 
-  if ([[input type] hasSuffix:@"popover"]) {
-    NSPopoverTouchBarItem* newPopoverItem =
-        [[NSPopoverTouchBarItem alloc] initWithIdentifier:aIdentifier];
-    // We initialize popoverTouchBar here because we only allow setting this
-    // property on popover creation. Updating popoverTouchBar for every update
-    // of the popover item would be very expensive.
-    newPopoverItem.popoverTouchBar = [[nsTouchBar alloc] initWithInputs:[input children]];
-    [self updatePopover:newPopoverItem input:input];
-    return newPopoverItem;
-  }
-
-  // Our new item, which will be initialized depending on aIdentifier.
-  NSCustomTouchBarItem* newItem = [[NSCustomTouchBarItem alloc] initWithIdentifier:aIdentifier];
-
-  if ([[input type] hasSuffix:@"scrollView"]) {
-    [self updateScrollView:newItem input:input];
-    return newItem;
-  } else if ([[input type] hasSuffix:@"label"]) {
-    NSTextField* label = [NSTextField labelWithString:@""];
-    [self updateLabel:label input:input];
-    newItem.view = label;
-    return newItem;
-  }
-
   // The cases of a button or main button require the same setup.
   NSButton* button = [NSButton buttonWithTitle:@"" target:self action:@selector(touchBarAction:)];
-  newItem.view = button;
-
-  if ([[input type] hasSuffix:@"button"] && ![[input type] hasPrefix:@"scrollView"]) {
-    [self updateButton:button input:input];
-  } else if ([[input type] hasSuffix:@"mainButton"]) {
-    [self updateMainButton:button input:input];
-  }
-  return newItem;
-}
+  NSCustomTouchBarItem* item = [[NSCustomTouchBarItem alloc] initWithIdentifier:aIdentifier];
+  item.view = button;
 
-- (bool)updateItem:(TouchBarInput*)aInput {
-  NSTouchBarItem* item = [self itemForIdentifier:[aInput nativeIdentifier]];
-  // If we can't immediately find item, there are three possibilities:
-  //   * It is a button in a ScrollView, which can't be found with itemForIdentifier; or
-  //   * It is contained within a popover; or
-  //   * It simply does not exist.
-  // We check for each possibility here.
-  if (!item) {
-    if ([self maybeUpdateScrollViewChild:aInput]) {
-      [self replaceMappedLayoutItem:aInput];
-      return true;
-    }
-    if ([self maybeUpdatePopoverChild:aInput]) {
-      [self replaceMappedLayoutItem:aInput];
-      return true;
-    }
-    return false;
+  TouchBarInput* input = self.mappedLayoutItems[aIdentifier];
+  if ([aIdentifier hasPrefix:CustomButtonIdentifier]) {
+    return [self updateButton:item input:input];
+  } else if ([aIdentifier hasPrefix:CustomMainButtonIdentifier]) {
+    return [self updateMainButton:item input:input];
   }
 
-  item.customizationLabel = [aInput title];
-  if ([[aInput type] hasSuffix:@"button"]) {
-    [self updateButton:(NSButton*)item.view input:aInput];
-  } else if ([[aInput type] hasSuffix:@"mainButton"]) {
-    [self updateMainButton:(NSButton*)item.view input:aInput];
-  } else if ([[aInput type] hasSuffix:@"scrollView"]) {
-    [self updateScrollView:(NSCustomTouchBarItem*)item input:aInput];
-  } else if ([[aInput type] hasSuffix:@"popover"]) {
-    [self updatePopover:(NSPopoverTouchBarItem*)item input:aInput];
-  } else if ([[aInput type] hasSuffix:@"label"]) {
-    [self updateLabel:(NSTextField*)item.view input:aInput];
-  }
-
-  [self replaceMappedLayoutItem:aInput];
-  return true;
-}
-
-- (bool)maybeUpdatePopoverChild:(TouchBarInput*)aInput {
-  for (NSTouchBarItemIdentifier identifier in self.mappedLayoutItems) {
-    TouchBarInput* potentialPopover = self.mappedLayoutItems[identifier];
-    if (![[potentialPopover type] hasSuffix:@"popover"]) {
-      continue;
-    }
-    NSTouchBarItem* popover = [self itemForIdentifier:[potentialPopover nativeIdentifier]];
-    if (popover) {
-      if ([(nsTouchBar*)[(NSPopoverTouchBarItem*)popover popoverTouchBar] updateItem:aInput]) {
-        return true;
-      }
-    }
-  }
-  return false;
+  return nil;
 }
 
-- (bool)maybeUpdateScrollViewChild:(TouchBarInput*)aInput {
-  NSButton* scrollViewButton = self.scrollViewButtons[[aInput nativeIdentifier]];
-  if (scrollViewButton) {
-    // ScrollView buttons are similar to mainButtons except for their width.
-    [self updateMainButton:scrollViewButton input:aInput];
-    uint32_t buttonSize =
-        MAX(scrollViewButton.attributedTitle.size.width + kInputIconSize + kInputSpacing,
-            kScrollViewButtonWidth);
-    [[scrollViewButton widthAnchor] constraintGreaterThanOrEqualToConstant:buttonSize].active = YES;
+- (void)updateItem:(TouchBarInput*)aInput {
+  NSTouchBarItem* item = [self itemForIdentifier:[aInput nativeIdentifier]];
+  if (!item) {
+    return;
   }
-  // Updating the TouchBarInput* in the ScrollView's mChildren array.
-  for (NSTouchBarItemIdentifier identifier in self.mappedLayoutItems) {
-    TouchBarInput* potentialScrollView = self.mappedLayoutItems[identifier];
-    if (![[potentialScrollView type] hasSuffix:@"scrollView"]) {
-      continue;
-    }
-    for (uint32_t i = 0; i < [[potentialScrollView children] count]; ++i) {
-      TouchBarInput* child = [potentialScrollView children][i];
-      if (![[child nativeIdentifier] isEqualToString:[aInput nativeIdentifier]]) {
-        continue;
-      }
-      [[potentialScrollView children] replaceObjectAtIndex:i withObject:aInput];
-      [child release];
-      return true;
-    }
+  if ([[aInput nativeIdentifier] hasPrefix:CustomButtonIdentifier]) {
+    [self updateButton:(NSCustomTouchBarItem*)item input:aInput];
+  } else if ([[aInput nativeIdentifier] hasPrefix:CustomMainButtonIdentifier]) {
+    [self updateMainButton:(NSCustomTouchBarItem*)item input:aInput];
   }
-  return false;
+
+  [self.mappedLayoutItems[[aInput nativeIdentifier]] release];
+  self.mappedLayoutItems[[aInput nativeIdentifier]] = aInput;
 }
 
-- (void)replaceMappedLayoutItem:(TouchBarInput*)aItem {
-  [self.mappedLayoutItems[[aItem nativeIdentifier]] release];
-  self.mappedLayoutItems[[aItem nativeIdentifier]] = aItem;
-}
-
-- (void)updateButton:(NSButton*)aButton input:(TouchBarInput*)aInput {
-  if (!aButton || !aInput) {
-    return;
+- (NSTouchBarItem*)updateButton:(NSCustomTouchBarItem*)aButton input:(TouchBarInput*)aInput {
+  NSButton* button = (NSButton*)aButton.view;
+  if (!button) {
+    return nil;
   }
 
-  aButton.title = [aInput title];
+  button.title = [aInput title];
   if (![aInput isIconPositionSet]) {
-    [aButton setImagePosition:NSImageOnly];
+    [button setImagePosition:NSImageOnly];
     [aInput setIconPositionSet:true];
   }
 
   if ([aInput imageURI]) {
     RefPtr<nsTouchBarInputIcon> icon = [aInput icon];
     if (!icon) {
-      icon = new nsTouchBarInputIcon([aInput document], aButton);
+      icon = new nsTouchBarInputIcon([aInput document], button);
       [aInput setIcon:icon];
     }
     icon->SetupIcon([aInput imageURI]);
   }
-  [aButton setEnabled:![aInput isDisabled]];
+  [button setEnabled:![aInput isDisabled]];
 
   if ([aInput color]) {
-    aButton.bezelColor = [aInput color];
+    button.bezelColor = [aInput color];
   }
 
-  objc_setAssociatedObject(aButton, &sIdentifierAssociationKey, [aInput nativeIdentifier],
+  objc_setAssociatedObject(button, &sIdentifierAssociationKey, [aInput nativeIdentifier],
                            OBJC_ASSOCIATION_RETAIN);
-}
-
-- (void)updateMainButton:(NSButton*)aMainButton input:(TouchBarInput*)aInput {
-  if (!aMainButton || !aInput) {
-    return;
-  }
-  // If empty, string is still being localized. Display a blank input instead.
-  if ([[aInput title] isEqualToString:@""]) {
-    [aMainButton setImagePosition:NSNoImage];
-  } else {
-    [aMainButton setImagePosition:NSImageLeft];
-  }
-  aMainButton.imageHugsTitle = YES;
-  [aInput setIconPositionSet:true];
 
-  [self updateButton:aMainButton input:aInput];
-  [aMainButton.widthAnchor constraintGreaterThanOrEqualToConstant:MAIN_BUTTON_WIDTH].active = YES;
-  [aMainButton setContentHuggingPriority:1.0
-                          forOrientation:NSLayoutConstraintOrientationHorizontal];
-}
+  aButton.customizationLabel = [aInput title];
 
-- (void)updatePopover:(NSPopoverTouchBarItem*)aPopoverItem input:(TouchBarInput*)aInput {
-  if (!aPopoverItem || !aInput) {
-    return;
-  }
-  aPopoverItem.showsCloseButton = YES;
-  if ([aInput imageURI]) {
-    RefPtr<nsTouchBarInputIcon> icon = [aInput icon];
-    if (!icon) {
-      icon = new nsTouchBarInputIcon([aInput document], nil, nil, aPopoverItem);
-      [aInput setIcon:icon];
-    }
-    icon->SetupIcon([aInput imageURI]);
-  } else if ([aInput title]) {
-    aPopoverItem.collapsedRepresentationLabel = [aInput title];
-  } else {
-    aPopoverItem.collapsedRepresentation = nil;
-  }
+  return aButton;
 }
 
-- (void)updateScrollView:(NSCustomTouchBarItem*)aScrollViewItem input:(TouchBarInput*)aInput {
-  if (!aScrollViewItem || ![aInput children]) {
-    return;
+- (NSTouchBarItem*)updateMainButton:(NSCustomTouchBarItem*)aMainButton
+                              input:(TouchBarInput*)aInput {
+  NSButton* button = (NSButton*)aMainButton.view;
+  // If empty, string is still being localized. Display a blank input instead.
+  if ([[aInput title] isEqualToString:@""]) {
+    [button setImagePosition:NSNoImage];
+  } else {
+    [button setImagePosition:NSImageLeft];
   }
-  NSMutableDictionary* constraintViews = [NSMutableDictionary dictionary];
-  NSView* documentView = [[NSView alloc] initWithFrame:NSZeroRect];
-  NSString* layoutFormat = @"H:|-8-";
-  NSSize size = NSMakeSize(kInputSpacing, 30);
-  // Layout strings allow only alphanumeric characters. We will use this
-  // NSCharacterSet to strip illegal characters.
-  NSCharacterSet* charactersToRemove = [[NSCharacterSet alphanumericCharacterSet] invertedSet];
-
-  for (TouchBarInput* childInput in [aInput children]) {
-    if (![[childInput type] hasSuffix:@"button"]) {
-      continue;
-    }
-    NSButton* button = [NSButton buttonWithTitle:[childInput title]
-                                          target:self
-                                          action:@selector(touchBarAction:)];
-    // ScrollView buttons are similar to mainButtons except for their width.
-    [self updateMainButton:button input:childInput];
-    uint32_t buttonSize = MAX(button.attributedTitle.size.width + kInputIconSize + kInputSpacing,
-                              kScrollViewButtonWidth);
-    [[button widthAnchor] constraintGreaterThanOrEqualToConstant:buttonSize].active = YES;
-
-    self.scrollViewButtons[[childInput nativeIdentifier]] = button;
+  button.imageHugsTitle = YES;
+  [aInput setIconPositionSet:true];
 
-    button.translatesAutoresizingMaskIntoConstraints = NO;
-    [documentView addSubview:button];
-    NSString* layoutKey = [[[childInput nativeIdentifier]
-        componentsSeparatedByCharactersInSet:charactersToRemove] componentsJoinedByString:@""];
-
-    // Iteratively create our layout string.
-    layoutFormat =
-        [layoutFormat stringByAppendingString:[NSString stringWithFormat:@"[%@]-8-", layoutKey]];
-    [constraintViews setObject:button forKey:layoutKey];
-    size.width += kInputSpacing + buttonSize;
-  }
-  layoutFormat = [layoutFormat stringByAppendingString:[NSString stringWithFormat:@"|"]];
-  NSArray* hConstraints =
-      [NSLayoutConstraint constraintsWithVisualFormat:layoutFormat
-                                              options:NSLayoutFormatAlignAllCenterY
-                                              metrics:nil
-                                                views:constraintViews];
-  NSScrollView* scrollView =
-      [[NSScrollView alloc] initWithFrame:CGRectMake(0, 0, size.width, size.height)];
-  [documentView setFrame:NSMakeRect(0, 0, size.width, size.height)];
-  [NSLayoutConstraint activateConstraints:hConstraints];
-  scrollView.documentView = documentView;
-
-  aScrollViewItem.view = scrollView;
-}
-
-- (void)updateLabel:(NSTextField*)aLabel input:aInput {
-  if (!aLabel || ![aInput title]) {
-    return;
-  }
-  [aLabel setStringValue:[aInput title]];
+  aMainButton = (NSCustomTouchBarItem*)[self updateButton:aMainButton input:aInput];
+  [button.widthAnchor constraintGreaterThanOrEqualToConstant:MAIN_BUTTON_WIDTH].active = YES;
+  [button setContentHuggingPriority:1.0 forOrientation:NSLayoutConstraintOrientationHorizontal];
+  return aMainButton;
 }
 
 - (NSTouchBarItem*)makeShareScrubberForIdentifier:(NSTouchBarItemIdentifier)aIdentifier {
   TouchBarInput* input = self.mappedLayoutItems[aIdentifier];
   // System-default share menu
   NSSharingServicePickerTouchBarItem* servicesItem =
       [[NSSharingServicePickerTouchBarItem alloc] initWithIdentifier:aIdentifier];
 
@@ -435,32 +205,16 @@ static const uint32_t kInputIconSize = 1
     }
     icon->SetupIcon([input imageURI]);
   }
 
   servicesItem.delegate = self;
   return servicesItem;
 }
 
-- (void)showPopover:(TouchBarInput*)aPopover showing:(bool)aShowing {
-  if (!aPopover) {
-    return;
-  }
-  NSPopoverTouchBarItem* popoverItem =
-      (NSPopoverTouchBarItem*)[self itemForIdentifier:[aPopover nativeIdentifier]];
-  if (!popoverItem) {
-    return;
-  }
-  if (aShowing) {
-    [popoverItem showPopover:self];
-  } else {
-    [popoverItem dismissPopover:self];
-  }
-}
-
 - (void)touchBarAction:(id)aSender {
   NSTouchBarItemIdentifier identifier =
       objc_getAssociatedObject(aSender, &sIdentifierAssociationKey);
   if (!identifier || [identifier isEqualToString:@""]) {
     return;
   }
 
   TouchBarInput* input = self.mappedLayoutItems[identifier];
@@ -477,33 +231,23 @@ static const uint32_t kInputIconSize = 1
   callback->OnCommand();
 }
 
 - (void)releaseJSObjects {
   mTouchBarHelper = nil;
 
   for (NSTouchBarItemIdentifier identifier in self.mappedLayoutItems) {
     TouchBarInput* input = self.mappedLayoutItems[identifier];
-    if (!input) {
-      continue;
+    RefPtr<nsTouchBarInputIcon> icon = [input icon];
+    if (icon) {
+      icon->ReleaseJSObjects();
     }
-
-    // Childless popovers contain the default Touch Bar as its popoverTouchBar.
-    // We check for [input children] since the default Touch Bar contains a
-    // popover (search-popover), so this would infinitely loop if there was no check.
-    if ([[input type] hasSuffix:@"popover"] && [input children]) {
-      NSTouchBarItem* item = [self itemForIdentifier:identifier];
-      [(nsTouchBar*)[(NSPopoverTouchBarItem*)item popoverTouchBar] releaseJSObjects];
-    }
-
     [input setCallback:nil];
     [input setDocument:nil];
     [input setImageURI:nil];
-
-    [input releaseJSObjects];
   }
 }
 
 #pragma mark - NSSharingServicePickerTouchBarItemDelegate
 
 - (NSArray*)itemsForSharingServicePickerTouchBarItem:
     (NSSharingServicePickerTouchBarItem*)aPickerTouchBarItem {
   NSURL* urlToShare = nil;
@@ -570,30 +314,27 @@ static const uint32_t kInputIconSize = 1
 }
 - (NSColor*)color {
   return mColor;
 }
 - (BOOL)isDisabled {
   return mDisabled;
 }
 - (NSTouchBarItemIdentifier)nativeIdentifier {
-  return [TouchBarInput nativeIdentifierWithType:mType withKey:mKey];
+  return mNativeIdentifier;
 }
 - (nsCOMPtr<nsITouchBarInputCallback>)callback {
   return mCallback;
 }
 - (RefPtr<Document>)document {
   return mDocument;
 }
 - (BOOL)isIconPositionSet {
   return mIsIconPositionSet;
 }
-- (NSMutableArray<TouchBarInput*>*)children {
-  return mChildren;
-}
 - (void)setKey:(NSString*)aKey {
   [aKey retain];
   [mKey release];
   mKey = aKey;
 }
 
 - (void)setTitle:(NSString*)aTitle {
   [aTitle retain];
@@ -620,81 +361,77 @@ static const uint32_t kInputIconSize = 1
   [mColor release];
   mColor = aColor;
 }
 
 - (void)setDisabled:(BOOL)aDisabled {
   mDisabled = aDisabled;
 }
 
+- (void)setNativeIdentifier:(NSTouchBarItemIdentifier)aNativeIdentifier {
+  [aNativeIdentifier retain];
+  [mNativeIdentifier release];
+  mNativeIdentifier = aNativeIdentifier;
+}
+
 - (void)setCallback:(nsCOMPtr<nsITouchBarInputCallback>)aCallback {
   mCallback = aCallback;
 }
 
 - (void)setDocument:(RefPtr<Document>)aDocument {
   if (mIcon) {
     mIcon->Destroy();
     mIcon = nil;
   }
   mDocument = aDocument;
 }
 
 - (void)setIconPositionSet:(BOOL)aIsIconPositionSet {
   mIsIconPositionSet = aIsIconPositionSet;
 }
 
-- (void)setChildren:(NSMutableArray<TouchBarInput*>*)aChildren {
-  [aChildren retain];
-  for (TouchBarInput* child in mChildren) {
-    [child releaseJSObjects];
-  }
-  [mChildren removeAllObjects];
-  [mChildren release];
-  mChildren = aChildren;
-}
-
 - (id)initWithKey:(NSString*)aKey
             title:(NSString*)aTitle
          imageURI:(nsCOMPtr<nsIURI>)aImageURI
              type:(NSString*)aType
          callback:(nsCOMPtr<nsITouchBarInputCallback>)aCallback
             color:(uint32_t)aColor
          disabled:(BOOL)aDisabled
-         document:(RefPtr<Document>)aDocument
-         children:(nsCOMPtr<nsIArray>)aChildren {
+         document:(RefPtr<Document>)aDocument {
   if (self = [super init]) {
     [self setKey:aKey];
     [self setTitle:aTitle];
     [self setImageURI:aImageURI];
     [self setType:aType];
     [self setCallback:aCallback];
     [self setDocument:aDocument];
     [self setIconPositionSet:false];
-    [self setDisabled:aDisabled];
     if (aColor) {
       [self setColor:[NSColor colorWithDisplayP3Red:((aColor >> 16) & 0xFF) / 255.0
                                               green:((aColor >> 8) & 0xFF) / 255.0
                                                blue:((aColor)&0xFF) / 255.0
                                               alpha:1.0]];
     }
-    if (aChildren) {
-      uint32_t itemCount = 0;
-      aChildren->GetLength(&itemCount);
-      NSMutableArray* orderedChildren = [NSMutableArray arrayWithCapacity:itemCount];
-      for (uint32_t i = 0; i < itemCount; ++i) {
-        nsCOMPtr<nsITouchBarInput> child = do_QueryElementAt(aChildren, i);
-        if (!child) {
-          continue;
-        }
-        TouchBarInput* convertedChild = [[TouchBarInput alloc] initWithXPCOM:child];
-        if (convertedChild) {
-          orderedChildren[i] = convertedChild;
-        }
-      }
-      [self setChildren:orderedChildren];
+    [self setDisabled:aDisabled];
+
+    NSTouchBarItemIdentifier TypeIdentifier = @"";
+    if ([aType isEqualToString:@"scrubber"]) {
+      TypeIdentifier = ScrubberIdentifier;
+    } else if ([aType isEqualToString:@"mainButton"]) {
+      TypeIdentifier = CustomMainButtonIdentifier;
+    } else {
+      TypeIdentifier = CustomButtonIdentifier;
+    }
+
+    if (!aKey) {
+      [self setNativeIdentifier:TypeIdentifier];
+    } else if ([aKey isEqualToString:@"share"]) {
+      [self setNativeIdentifier:[TypeIdentifier stringByAppendingPathExtension:aKey]];
+    } else {
+      [self setNativeIdentifier:[TypeIdentifier stringByAppendingPathExtension:aKey]];
     }
   }
 
   return self;
 }
 
 - (TouchBarInput*)initWithXPCOM:(nsCOMPtr<nsITouchBarInput>)aInput {
   nsAutoString keyStr;
@@ -740,61 +477,32 @@ static const uint32_t kInputIconSize = 1
   }
 
   RefPtr<Document> document;
   rv = aInput->GetDocument(getter_AddRefs(document));
   if (NS_FAILED(rv)) {
     return nil;
   }
 
-  nsCOMPtr<nsIArray> children;
-  rv = aInput->GetChildren(getter_AddRefs(children));
-  if (NS_FAILED(rv)) {
-    return nil;
-  }
-
   return [self initWithKey:nsCocoaUtils::ToNSString(keyStr)
                      title:nsCocoaUtils::ToNSString(titleStr)
                   imageURI:imageURI
                       type:nsCocoaUtils::ToNSString(typeStr)
                   callback:callback
                      color:colorInt
                   disabled:(BOOL)disabled
-                  document:document
-                  children:children];
-}
-
-- (void)releaseJSObjects {
-  if (mIcon) {
-    mIcon->ReleaseJSObjects();
-  }
-  mCallback = nil;
-  mImageURI = nil;
-  mDocument = nil;
-  for (TouchBarInput* child in mChildren) {
-    [child releaseJSObjects];
-  }
+                  document:document];
 }
 
 - (void)dealloc {
   if (mIcon) {
     mIcon->Destroy();
     mIcon = nil;
   }
   [mKey release];
   [mTitle release];
   [mType release];
   [mColor release];
-  [mChildren removeAllObjects];
-  [mChildren release];
+  [mNativeIdentifier release];
   [super dealloc];
 }
 
-+ (NSTouchBarItemIdentifier)nativeIdentifierWithType:(NSString*)aType withKey:(NSString*)aKey {
-  NSTouchBarItemIdentifier identifier;
-  identifier = [BaseIdentifier stringByAppendingPathExtension:aType];
-  if (aKey) {
-    identifier = [identifier stringByAppendingPathExtension:aKey];
-  }
-  return identifier;
-}
-
 @end

--- a/widget/cocoa/nsTouchBarInputIcon.h
+++ b/widget/cocoa/nsTouchBarInputIcon.h
@@ -21,19 +21,19 @@ using namespace mozilla::dom;
 class nsIconLoaderService;
 class nsIURI;
 class nsIPrincipal;
 class imgRequestProxy;
 
 class nsTouchBarInputIcon : public nsIconLoaderObserver {
  public:
   explicit nsTouchBarInputIcon(
-      RefPtr<Document> aDocument, NSButton* aButton,
-      NSSharingServicePickerTouchBarItem* aShareScrubber = nil,
-      NSPopoverTouchBarItem* aPopoverItem = nil);
+      RefPtr<Document> aDocument,
+      NSButton* aButton,
+      NSSharingServicePickerTouchBarItem* aShareScrubber = nil);
 
  private:
   virtual ~nsTouchBarInputIcon();
 
  public:
   // SetupIcon succeeds if it was able to set up the icon, or if there should
   // be no icon, in which case it clears any existing icon but still succeeds.
   nsresult SetupIcon(nsCOMPtr<nsIURI> aIconURI);
@@ -54,16 +54,14 @@ class nsTouchBarInputIcon : public nsIco
   RefPtr<Document> mDocument;
   nsIntRect mImageRegionRect;
   bool mSetIcon;
   NSButton* mButton;
   // We accept a mShareScrubber only as a special case since
   // NSSharingServicePickerTouchBarItem does not expose an NSButton* on which we
   // can set the `image` property.
   NSSharingServicePickerTouchBarItem* mShareScrubber;
-  // We accept a popover only as a special case.
-  NSPopoverTouchBarItem* mPopoverItem;
   // The icon loader object should never outlive its creating
   // nsTouchBarInputIcon object.
   RefPtr<nsIconLoaderService> mIconLoader;
 };
 
 #endif  // nsTouchBarInputIcon_h_

--- a/widget/cocoa/nsTouchBarInputIcon.mm
+++ b/widget/cocoa/nsTouchBarInputIcon.mm
@@ -17,24 +17,20 @@
 #include "nsNameSpaceManager.h"
 #include "nsObjCExceptions.h"
 
 using namespace mozilla;
 
 static const uint32_t kIconSize = 16;
 static const CGFloat kHiDPIScalingFactor = 2.0f;
 
-nsTouchBarInputIcon::nsTouchBarInputIcon(RefPtr<Document> aDocument, NSButton* aButton,
-                                         NSSharingServicePickerTouchBarItem* aShareScrubber,
-                                         NSPopoverTouchBarItem* aPopoverItem)
-    : mDocument(aDocument),
-      mSetIcon(false),
-      mButton(aButton),
-      mShareScrubber(aShareScrubber),
-      mPopoverItem(aPopoverItem) {
+nsTouchBarInputIcon::nsTouchBarInputIcon(RefPtr<Document> aDocument,
+                                         NSButton* aButton,
+                                         NSSharingServicePickerTouchBarItem* aShareScrubber)
+    : mDocument(aDocument), mSetIcon(false), mButton(aButton), mShareScrubber(aShareScrubber) {
   MOZ_COUNT_CTOR(nsTouchBarInputIcon);
 }
 
 nsTouchBarInputIcon::~nsTouchBarInputIcon() {
   Destroy();
   MOZ_COUNT_DTOR(nsTouchBarInputIcon);
 }
 
@@ -44,24 +40,23 @@ nsTouchBarInputIcon::~nsTouchBarInputIco
 void nsTouchBarInputIcon::Destroy() {
   if (mIconLoader) {
     mIconLoader->Destroy();
     mIconLoader = nullptr;
   }
 
   mButton = nil;
   mShareScrubber = nil;
-  mPopoverItem = nil;
 }
 
 nsresult nsTouchBarInputIcon::SetupIcon(nsCOMPtr<nsIURI> aIconURI) {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;
 
   // Still don't have one, then something is wrong, get out of here.
-  if (!(mButton || mShareScrubber || mPopoverItem)) {
+  if (!(mButton || mShareScrubber)) {
     NS_ERROR("No Touch Bar button");
     return NS_ERROR_FAILURE;
   }
 
   if (!mIconLoader) {
     // We ask only for the HiDPI images since all Touch Bars are Retina
     // displays and we have no need for icons @1x.
     mIconLoader = new nsIconLoaderService(mDocument, &mImageRegionRect, this, kIconSize, kIconSize,
@@ -70,40 +65,37 @@ nsresult nsTouchBarInputIcon::SetupIcon(
       return NS_ERROR_OUT_OF_MEMORY;
     }
   }
 
   if (!mSetIcon) {
     // Load placeholder icon.
     [mButton setImage:mIconLoader->GetNativeIconImage()];
     [mShareScrubber setButtonImage:mIconLoader->GetNativeIconImage()];
-    [mPopoverItem setCollapsedRepresentationImage:mIconLoader->GetNativeIconImage()];
   }
 
   nsresult rv = mIconLoader->LoadIcon(aIconURI);
   if (NS_FAILED(rv)) {
     // There is no icon for this menu item, as an error occurred while loading it.
     // An icon might have been set earlier or the place holder icon may have
     // been set.  Clear it.
     [mButton setImage:nil];
     [mShareScrubber setButtonImage:nil];
-    [mPopoverItem setCollapsedRepresentationImage:nil];
   }
 
   mSetIcon = true;
 
   return rv;
 
   NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
 }
 
 //
 // nsIconLoaderObserver
 //
 
 nsresult nsTouchBarInputIcon::OnComplete(NSImage* aImage) {
   [mButton setImage:aImage];
   [mShareScrubber setButtonImage:aImage];
-  [mPopoverItem setCollapsedRepresentationImage:aImage];
 
   [aImage release];
   return NS_OK;
 }

--- a/widget/cocoa/nsTouchBarNativeAPIDefines.h
+++ b/widget/cocoa/nsTouchBarNativeAPIDefines.h
@@ -14,65 +14,50 @@
 @end
 
 @interface NSColor (DisplayP3Colors)
 + (NSColor*)colorWithDisplayP3Red:(CGFloat)red
                             green:(CGFloat)green
                              blue:(CGFloat)blue
                             alpha:(CGFloat)alpha;
 @end
-
-@interface NSTextField (NewConstructors)
-+ (NSTextField*)labelWithString:(NSString*)stringValue;
-@end
 #endif  // !defined(MAC_OS_X_VERSION_10_12)
 
 #if !defined(MAC_OS_X_VERSION_10_12_2) || MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_12_2
 @interface NSApplication (TouchBarMenu)
 - (IBAction)toggleTouchBarCustomizationPalette:(id)sender;
 @end
 
 typedef NSString* NSTouchBarItemIdentifier;
 __attribute__((weak_import)) @interface NSTouchBarItem : NSObject
-@property(readonly) NSView* view;
-@property(strong) NSString* customizationLabel;
 - (instancetype)initWithIdentifier:(NSTouchBarItemIdentifier)aIdentifier;
 @end
 
 @protocol NSSharingServicePickerTouchBarItemDelegate
 @end
 
 __attribute__((weak_import)) @interface NSSharingServicePickerTouchBarItem : NSTouchBarItem
 @property(strong) id<NSSharingServicePickerTouchBarItemDelegate> delegate;
 @property(strong) NSImage* buttonImage;
 @end
 
 __attribute__((weak_import)) @interface NSCustomTouchBarItem : NSTouchBarItem
 @property(strong) NSView* view;
+@property(strong) NSString* customizationLabel;
 @end
 
 @protocol NSTouchBarDelegate
 @end
 
 typedef NSString* NSTouchBarCustomizationIdentifier;
 __attribute__((weak_import)) @interface NSTouchBar : NSObject
 @property(strong) NSArray<NSTouchBarItemIdentifier>* defaultItemIdentifiers;
 @property(strong) id<NSTouchBarDelegate> delegate;
 @property(strong) NSTouchBarCustomizationIdentifier customizationIdentifier;
 @property(strong) NSArray<NSTouchBarItemIdentifier>* customizationAllowedItemIdentifiers;
 - (NSTouchBarItem*)itemForIdentifier:(NSTouchBarItemIdentifier)aIdentifier;
 @end
 
-__attribute__((weak_import)) @interface NSPopoverTouchBarItem : NSTouchBarItem
-@property(strong) NSView* collapsedRepresentation;
-@property(strong) NSImage* collapsedRepresentationImage;
-@property(strong) NSString* collapsedRepresentationLabel;
-@property(strong) NSTouchBar* popoverTouchBar;
-@property BOOL showsCloseButton;
-- (void)showPopover:(id)sender;
-- (void)dismissPopover:(id)sender;
-@end
-
 @interface NSButton (TouchBarButton)
 @property(strong) NSColor* bezelColor;
 @end
 #endif  // !defined(MAC_OS_X_VERSION_10_12_2)
 #endif  // nsTouchBarNativeAPIDefines_h

--- a/widget/cocoa/nsTouchBarUpdater.h
+++ b/widget/cocoa/nsTouchBarUpdater.h
@@ -1,23 +1,21 @@
 /* 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/. */
 
 #ifndef nsTouchBarUpdater_h_
 #define nsTouchBarUpdater_h_
 
 #include "nsITouchBarUpdater.h"
-#include "nsCocoaWindow.h"
 
 class nsTouchBarUpdater : public nsITouchBarUpdater {
  public:
   nsTouchBarUpdater() {}
 
   NS_DECL_ISUPPORTS
   NS_DECL_NSITOUCHBARUPDATER
 
  protected:
   virtual ~nsTouchBarUpdater() {}
-  BaseWindow* GetCocoaWindow(nsIBaseWindow* aWindow);
 };
 
 #endif  // nsTouchBarUpdater_h_

--- a/widget/cocoa/nsTouchBarUpdater.mm
+++ b/widget/cocoa/nsTouchBarUpdater.mm
@@ -4,16 +4,17 @@
 
 #import <Cocoa/Cocoa.h>
 
 #include "nsTouchBar.h"
 #include "nsITouchBarInput.h"
 #include "nsTouchBarUpdater.h"
 #include "nsTouchBarNativeAPIDefines.h"
 
+#include "nsCocoaWindow.h"
 #include "nsIArray.h"
 #include "nsIBaseWindow.h"
 #include "nsIWidget.h"
 
 // defined in nsCocoaWindow.mm.
 extern BOOL sTouchBarIsInitialized;
 
 #if !defined(MAC_OS_X_VERSION_10_12_2) || MAC_OS_X_VERSION_MAX_ALLOWED < MAC_OS_X_VERSION_10_12_2
@@ -22,21 +23,22 @@ extern BOOL sTouchBarIsInitialized;
 @end
 #endif
 
 NS_IMPL_ISUPPORTS(nsTouchBarUpdater, nsITouchBarUpdater);
 
 NS_IMETHODIMP
 nsTouchBarUpdater::UpdateTouchBarInputs(nsIBaseWindow* aWindow,
                                         const nsTArray<RefPtr<nsITouchBarInput>>& aInputs) {
-  if (!sTouchBarIsInitialized) {
-    return NS_OK;
+  nsCOMPtr<nsIWidget> widget = nullptr;
+  aWindow->GetMainWidget(getter_AddRefs(widget));
+  if (!widget) {
+    return NS_ERROR_FAILURE;
   }
-
-  BaseWindow* cocoaWin = nsTouchBarUpdater::GetCocoaWindow(aWindow);
+  BaseWindow* cocoaWin = (BaseWindow*)widget->GetNativeData(NS_NATIVE_WINDOW);
   if (!cocoaWin) {
     return NS_ERROR_FAILURE;
   }
 
   if ([cocoaWin respondsToSelector:@selector(touchBar)]) {
     size_t itemCount = aInputs.Length();
     for (size_t i = 0; i < itemCount; ++i) {
       nsCOMPtr<nsITouchBarInput> input(aInputs.ElementAt(i));
@@ -48,74 +50,25 @@ nsTouchBarUpdater::UpdateTouchBarInputs(
       [(nsTouchBar*)cocoaWin.touchBar updateItem:convertedInput];
     }
   }
 
   return NS_OK;
 }
 
 NS_IMETHODIMP
-nsTouchBarUpdater::ShowPopover(nsIBaseWindow* aWindow, nsITouchBarInput* aPopover, bool aShowing) {
-  if (!sTouchBarIsInitialized || !aPopover) {
-    return NS_OK;
-  }
-
-  BaseWindow* cocoaWin = nsTouchBarUpdater::GetCocoaWindow(aWindow);
-  if (!cocoaWin) {
-    return NS_ERROR_FAILURE;
-  }
-
-  if ([cocoaWin respondsToSelector:@selector(touchBar)]) {
-    // We don't need to completely reinitialize the popover. We only need its
-    // identifier to look it up in [nsTouchBar mappedLayoutItems].
-    nsAutoString keyStr;
-    nsresult rv = aPopover->GetKey(keyStr);
-    if (NS_FAILED(rv)) {
-      return NS_ERROR_FAILURE;
-    }
-    NSString* key = nsCocoaUtils::ToNSString(keyStr);
-
-    nsAutoString typeStr;
-    rv = aPopover->GetType(typeStr);
-    if (NS_FAILED(rv)) {
-      return NS_ERROR_FAILURE;
-    }
-    NSString* type = nsCocoaUtils::ToNSString(typeStr);
-
-    TouchBarInput* popoverItem = [[(nsTouchBar*)cocoaWin.touchBar mappedLayoutItems]
-        objectForKey:[TouchBarInput nativeIdentifierWithType:type withKey:key]];
-
-    [(nsTouchBar*)cocoaWin.touchBar showPopover:popoverItem showing:aShowing];
-  }
-  return NS_OK;
-}
-
-NS_IMETHODIMP
 nsTouchBarUpdater::EnterCustomizeMode() {
   [NSApp toggleTouchBarCustomizationPalette:(id)this];
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsTouchBarUpdater::IsTouchBarInitialized(bool* aResult) {
   *aResult = sTouchBarIsInitialized;
   return NS_OK;
 }
 
-BaseWindow* nsTouchBarUpdater::GetCocoaWindow(nsIBaseWindow* aWindow) {
-  nsCOMPtr<nsIWidget> widget = nullptr;
-  aWindow->GetMainWidget(getter_AddRefs(widget));
-  if (!widget) {
-    return nil;
-  }
-  BaseWindow* cocoaWin = (BaseWindow*)widget->GetNativeData(NS_NATIVE_WINDOW);
-  if (!cocoaWin) {
-    return nil;
-  }
-  return cocoaWin;
-}
-
 // NOTE: This method is for internal unit tests only.
 NS_IMETHODIMP
 nsTouchBarUpdater::SetTouchBarInitialized(bool aIsInitialized) {
   sTouchBarIsInitialized = aIsInitialized;
   return NS_OK;
 }

--- a/widget/nsITouchBarHelper.idl
+++ b/widget/nsITouchBarHelper.idl
@@ -18,30 +18,19 @@ interface nsITouchBarHelper : nsISupport
   readonly attribute AString activeUrl;
 
   /**
    * Return the active browser's page title.
    */
   readonly attribute AString activeTitle;
 
   /**
-   * Return true if the Urlbar has focus.
-   */
-  readonly attribute boolean isUrlbarFocused;
-
-  /**
    * Returns all available Touch Bar Inputs in an nsIArray
    * of nsITouchBarInput objects.
    */
   attribute nsIArray allItems;
 
   /**
    * Returns the requested TouchBarInput.
    * Exposed for testing.
    */
   nsITouchBarInput getTouchBarInput(in string aInputName);
-
-  /**
-   * Inserts a search restriction string in the Urlbar.
-   * Exposed for testing.
-   */
-  void insertRestrictionInUrlbar(in string aToken);
 };

--- a/widget/nsITouchBarInput.idl
+++ b/widget/nsITouchBarInput.idl
@@ -60,15 +60,9 @@ interface nsITouchBarInput : nsISupports
    */
   attribute boolean disabled;
 
   /**
    * The context in which this nsITouchBarInput exists. Required to create
    * an imgLoader to load our SVG icons.
    */
   readonly attribute Document document;
-
-  /**
-   * An array containing an input's children.
-   * Available for  type = ("scrollView" || "popover").
-   */
-  attribute nsIArray children;
 };

--- a/widget/nsITouchBarUpdater.idl
+++ b/widget/nsITouchBarUpdater.idl
@@ -29,14 +29,9 @@ interface nsITouchBarUpdater : nsISuppor
   boolean isTouchBarInitialized();
 
   /**
    * Sets whether the Touch Bar is initialized.
    * NOTE: This method is for internal unit tests only! Normally, the system
    * sets this value after a Touch Bar is initialized on compatible Macs.
    */
   void setTouchBarInitialized(in boolean aIsInitialized);
-
-  /**
-   * If aShowing is true, aPopover is shown. Otherwise, it is hidden.
-   */
-  void showPopover(in nsIBaseWindow aWindow, in nsITouchBarInput aPopover, in boolean aShowing);
 };