--- a/devtools/client/framework/toolbox-options.js
+++ b/devtools/client/framework/toolbox-options.js
@@ -317,21 +317,16 @@ OptionsPanel.prototype = {
       label: "Enable new console frontend",
       id: "devtools-new-webconsole",
       parentId: "webconsole-options"
     }, {
       pref: "devtools.debugger.new-debugger-frontend",
       label: "Enable new debugger frontend",
       id: "devtools-new-debugger",
       parentId: "debugger-options"
-    }, {
-      pref: "devtools.layoutview.enabled",
-      label: "Enable layout panel",
-      id: "devtools-layout-panel",
-      parentId: "inspector-options"
     }];
 
     let createPreferenceOption = ({pref, label, id}) => {
       let inputLabel = this.panelDoc.createElement("label");
       let checkbox = this.panelDoc.createElement("input");
       checkbox.setAttribute("type", "checkbox");
       if (GetPref(pref)) {
         checkbox.setAttribute("checked", "checked");

--- a/devtools/client/inspector/boxmodel/test/head.js
+++ b/devtools/client/inspector/boxmodel/test/head.js
@@ -6,20 +6,18 @@
 /* import-globals-from ../../test/head.js */
 "use strict";
 
 // Import the inspector's head.js first (which itself imports shared-head.js).
 Services.scriptloader.loadSubScript(
   "chrome://mochitests/content/browser/devtools/client/inspector/test/head.js",
   this);
 
-Services.prefs.setBoolPref("devtools.layoutview.enabled", true);
 Services.prefs.setIntPref("devtools.toolbox.footer.height", 350);
 registerCleanupFunction(() => {
-  Services.prefs.clearUserPref("devtools.layoutview.enabled");
   Services.prefs.clearUserPref("devtools.toolbox.footer.height");
 });
 
 /**
  * Highlight a node and set the inspector's current selection to the node or
  * the first match of the given css selector.
  *
  * @param  {String|NodeFront} selectorOrNodeFront

--- a/devtools/client/inspector/grids/test/head.js
+++ b/devtools/client/inspector/grids/test/head.js
@@ -11,21 +11,19 @@ Services.scriptloader.loadSubScript(
   "chrome://mochitests/content/browser/devtools/client/inspector/test/head.js",
   this);
 
 // Load the shared Redux helpers into this compartment.
 Services.scriptloader.loadSubScript(
   "chrome://mochitests/content/browser/devtools/client/framework/test/shared-redux-head.js",
   this);
 
-Services.prefs.setBoolPref("devtools.layoutview.enabled", true);
 Services.prefs.setBoolPref("devtools.promote.layoutview.showPromoteBar", false);
 Services.prefs.setIntPref("devtools.toolbox.footer.height", 350);
 registerCleanupFunction(() => {
-  Services.prefs.clearUserPref("devtools.layoutview.enabled");
   Services.prefs.clearUserPref("devtools.promote.layoutview.showPromoteBar");
   Services.prefs.clearUserPref("devtools.toolbox.footer.height");
 });
 
 const HIGHLIGHTER_TYPE = "CssGridHighlighter";
 
 /**
  * Simulate a color change in a given color picker tooltip.

--- a/devtools/client/inspector/inspector.js
+++ b/devtools/client/inspector/inspector.js
@@ -615,24 +615,22 @@ Inspector.prototype = {
       INSPECTOR_L10N.getStr("inspector.sidebar.ruleViewTitle"),
       defaultTab == "ruleview");
 
     this.sidebar.addExistingTab(
       "computedview",
       INSPECTOR_L10N.getStr("inspector.sidebar.computedViewTitle"),
       defaultTab == "computedview");
 
-    if (Services.prefs.getBoolPref("devtools.layoutview.enabled")) {
-      // Grid and layout panels aren't lazy-loaded as their module end up
-      // calling inspector.addSidebarTab
-      this.gridInspector = new GridInspector(this, this.panelWin);
+    // Grid and layout panels aren't lazy-loaded as their module end up
+    // calling inspector.addSidebarTab
+    this.gridInspector = new GridInspector(this, this.panelWin);
 
-      const LayoutView = this.browserRequire("devtools/client/inspector/layout/layout");
-      this.layoutview = new LayoutView(this, this.panelWin);
-    }
+    const LayoutView = this.browserRequire("devtools/client/inspector/layout/layout");
+    this.layoutview = new LayoutView(this, this.panelWin);
 
     if (this.target.form.animationsActor) {
       this.sidebar.addFrameTab(
         "animationinspector",
         INSPECTOR_L10N.getStr("inspector.sidebar.animationInspectorTitle"),
         "chrome://devtools/content/animationinspector/animation-inspector.xhtml",
         defaultTab == "animationinspector");
     }

--- a/devtools/client/inspector/rules/test/browser_rules_eyedropper.js
+++ b/devtools/client/inspector/rules/test/browser_rules_eyedropper.js
@@ -109,15 +109,15 @@ function* testSelect(view, swatch, inspe
 function* openEyedropper(view, swatch) {
   let tooltip = view.tooltips.getTooltip("colorPicker").tooltip;
 
   info("Click on the swatch");
   let onColorPickerReady = view.tooltips.getTooltip("colorPicker").once("ready");
   swatch.click();
   yield onColorPickerReady;
 
-  let dropperButton = tooltip.doc.querySelector("#eyedropper-button");
+  let dropperButton = tooltip.container.querySelector("#eyedropper-button");
 
   info("Click on the eyedropper icon");
   let onOpened = tooltip.once("eyedropper-opened");
   dropperButton.click();
   yield onOpened;
 }

--- a/devtools/client/inspector/test/browser_inspector_highlighter-eyedropper-xul.js
+++ b/devtools/client/inspector/test/browser_inspector_highlighter-eyedropper-xul.js
@@ -26,17 +26,17 @@ add_task(function* () {
   let swatchEl = ruleViewDocument.querySelector(".ruleview-colorswatch");
 
   info("Open the color picker");
   let cPicker = ruleView.tooltips.getTooltip("colorPicker");
   let onColorPickerReady = cPicker.once("ready");
   swatchEl.click();
   yield onColorPickerReady;
 
-  button = cPicker.tooltip.doc.querySelector("#eyedropper-button");
+  button = cPicker.tooltip.container.querySelector("#eyedropper-button");
   ok(isDisabled(button), "The button is disabled in the color picker");
 
   info("Navigate to a HTML document");
   yield navigateTo(inspector, TEST_URL_2);
 
   info("Check the inspector toolbar in HTML document");
   button = inspector.panelDoc.querySelector("#inspector-eyedropper-toggle");
   ok(!isDisabled(button), "The button is enabled in the toolbar");
@@ -50,15 +50,15 @@ add_task(function* () {
   swatchEl = ruleViewDocument.querySelector(".ruleview-colorswatch");
 
   info("Open the color picker in HTML document");
   cPicker = ruleView.tooltips.getTooltip("colorPicker");
   onColorPickerReady = cPicker.once("ready");
   swatchEl.click();
   yield onColorPickerReady;
 
-  button = cPicker.tooltip.doc.querySelector("#eyedropper-button");
+  button = cPicker.tooltip.container.querySelector("#eyedropper-button");
   ok(!isDisabled(button), "The button is enabled in the color picker");
 });
 
 function isDisabled(button) {
   return button.disabled;
 }

--- a/devtools/client/locales/en-US/layout.properties
+++ b/devtools/client/locales/en-US/layout.properties
@@ -1,16 +1,14 @@
 # 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/.
 
 # LOCALIZATION NOTE This file contains the Layout Inspector strings.
 # The Layout Inspector is a panel accessible in the Inspector sidebar.
-# The Layout Inspector may need to be enabled in about:config by setting
-# devtools.layoutview.enabled to true.
 
 # LOCALIZATION NOTE (layout.cannotShowGridOutline, layout.cannotSHowGridOutline.title):
 # In the case where the grid outline cannot be effectively displayed.
 layout.cannotShowGridOutline=Cannot show outline for this grid
 layout.cannotShowGridOutline.title=The selected grid’s outline cannot effectively fit inside the layout panel for it to be usable.
 
 # LOCALIZATION NOTE (layout.displayGridAreas): Label of the display grid areas setting
 # option in the CSS Grid pane.

--- a/devtools/client/preferences/devtools.js
+++ b/devtools/client/preferences/devtools.js
@@ -63,19 +63,16 @@ pref("devtools.inspector.showAllAnonymou
 // Enable the MDN docs tooltip
 pref("devtools.inspector.mdnDocsTooltip.enabled", false);
 // Enable the new color widget
 pref("devtools.inspector.colorWidget.enabled", false);
 
 // Enable the Font Inspector
 pref("devtools.fontinspector.enabled", true);
 
-// Enable the Layout View
-pref("devtools.layoutview.enabled", false);
-
 // Counter to promote the inspector layout view.
 // @remove after release 56 (See Bug 1355747)
 pref("devtools.promote.layoutview", 1);
 // Whether or not to show the promote bar in the layout view
 // @remove after release 56 (See Bug 1355747)
 pref("devtools.promote.layoutview.showPromoteBar", true);
 
 // Grid highlighter preferences