--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -968,19 +968,16 @@ pref("browser.security.newcerterrorpage.
 pref("browser.security.newcerterrorpage.mitm.enabled", false);
 #endif
 
 pref("security.certerrors.recordEventTelemetry", true);
 
 // Whether to start the private browsing mode at application startup
 pref("browser.privatebrowsing.autostart", false);
 
-// Whether to show the new private browsing UI with in-content search box.
-pref("browser.privatebrowsing.searchUI", true);
-
 // Whether the bookmark panel should be shown when bookmarking a page.
 pref("browser.bookmarks.editDialog.showForNewBookmarks", true);
 
 // Don't try to alter this pref, it'll be reset the next time you use the
 // bookmarking dialog
 pref("browser.bookmarks.editDialog.firstEditField", "namePicker");
 
 pref("dom.ipc.plugins.flash.disable-protected-mode", false);

--- a/browser/components/about/AboutPrivateBrowsingHandler.jsm
+++ b/browser/components/about/AboutPrivateBrowsingHandler.jsm
@@ -2,23 +2,21 @@
  * 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/. */
 
 "use strict";
 
 var EXPORTED_SYMBOLS = ["AboutPrivateBrowsingHandler"];
 
 ChromeUtils.import("resource://gre/modules/remotepagemanager/RemotePageManagerParent.jsm");
-ChromeUtils.import("resource://gre/modules/Services.jsm");
 
 var AboutPrivateBrowsingHandler = {
   _topics: [
     "DontShowIntroPanelAgain",
     "OpenPrivateWindow",
-    "SearchHandoff",
   ],
 
   init() {
     this.pageListener = new RemotePages("about:privatebrowsing");
     for (let topic of this._topics) {
       this.pageListener.addMessageListener(topic, this.receiveMessage.bind(this));
     }
   },
@@ -37,72 +35,11 @@ var AboutPrivateBrowsingHandler = {
         win.OpenBrowserWindow({private: true});
         break;
       }
       case "DontShowIntroPanelAgain": {
         let win = aMessage.target.browser.ownerGlobal;
         win.ContentBlocking.dontShowIntroPanelAgain();
         break;
       }
-      case "SearchHandoff": {
-        let searchAlias = "";
-        let searchAliases = Services.search.defaultEngine.wrappedJSObject.__internalAliases;
-        if (searchAliases && searchAliases.length > 0) {
-          searchAlias = `${searchAliases[0]} `;
-        }
-        let urlBar = aMessage.target.browser.ownerGlobal.gURLBar;
-        let isFirstChange = true;
-
-        if (!aMessage.data || !aMessage.data.text) {
-          urlBar.hiddenFocus();
-        } else {
-          // Pass the provided text to the awesomebar. Prepend the @engine shortcut.
-          urlBar.search(`${searchAlias}${aMessage.data.text}`);
-          isFirstChange = false;
-        }
-
-        let checkFirstChange = () => {
-          // Check if this is the first change since we hidden focused. If it is,
-          // remove hidden focus styles, prepend the search alias and hide the
-          // in-content search.
-          if (isFirstChange) {
-            isFirstChange = false;
-            urlBar.removeHiddenFocus();
-            urlBar.search(searchAlias);
-            aMessage.target.sendAsyncMessage("HideSearch");
-            urlBar.removeEventListener("compositionstart", checkFirstChange);
-            urlBar.removeEventListener("paste", checkFirstChange);
-          }
-        };
-
-        let onKeydown = ev => {
-          // Check if the keydown will cause a value change.
-          if (ev.key.length === 1 && !ev.altKey && !ev.ctrlKey && !ev.metaKey) {
-            checkFirstChange();
-          }
-          // If the Esc button is pressed, we are done. Show in-content search and cleanup.
-          if (ev.key === "Escape") {
-            onDone();
-          }
-        };
-
-        let onDone = () => {
-          // We are done. Show in-content search again and cleanup.
-          aMessage.target.sendAsyncMessage("ShowSearch");
-          urlBar.removeHiddenFocus();
-
-          urlBar.removeEventListener("keydown", onKeydown);
-          urlBar.removeEventListener("mousedown", onDone);
-          urlBar.removeEventListener("blur", onDone);
-          urlBar.removeEventListener("compositionstart", checkFirstChange);
-          urlBar.removeEventListener("paste", checkFirstChange);
-        };
-
-        urlBar.addEventListener("keydown", onKeydown);
-        urlBar.addEventListener("mousedown", onDone);
-        urlBar.addEventListener("blur", onDone);
-        urlBar.addEventListener("compositionstart", checkFirstChange);
-        urlBar.addEventListener("paste", checkFirstChange);
-        break;
-      }
     }
   },
 };

--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -87,17 +87,17 @@ let ACTORS = {
       },
     },
   },
 
   ContentSearch: {
     child: {
       module: "resource:///actors/ContentSearchChild.jsm",
       group: "browsers",
-      matches: ["about:home", "about:newtab", "about:welcome", "about:privatebrowsing",
+      matches: ["about:home", "about:newtab", "about:welcome",
                 "chrome://mochitests/content/*"],
       events: {
         "ContentSearchClient": {capture: true, wantUntrusted: true},
       },
       messages: [
         "ContentSearch",
       ],
     },

--- a/browser/components/privatebrowsing/content/aboutPrivateBrowsing.css
+++ b/browser/components/privatebrowsing/content/aboutPrivateBrowsing.css
@@ -1,8 +1,6 @@
 html.private .showNormal,
 html.normal .showPrivate,
-html.search-ui .dontShowSearch,
-html.no-search-ui .showSearch,
 body[tpEnabled] .showTpDisabled,
 body:not([tpEnabled]) .showTpEnabled {
   display: none !important;
 }

--- a/browser/components/privatebrowsing/content/aboutPrivateBrowsing.js
+++ b/browser/components/privatebrowsing/content/aboutPrivateBrowsing.js
@@ -1,16 +1,15 @@
 /* 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/. */
 
 /* eslint-env mozilla/frame-script */
 
 const TP_PB_ENABLED_PREF = "privacy.trackingprotection.pbmode.enabled";
-const PB_SEARCH_UI_ENABLED_PREF = "browser.privatebrowsing.searchUI";
 
 document.addEventListener("DOMContentLoaded", function() {
   if (!RPMIsWindowPrivate()) {
     document.documentElement.classList.remove("private");
     document.documentElement.classList.add("normal");
     document.getElementById("startPrivateBrowsing").addEventListener("click", function() {
       RPMSendAsyncMessage("OpenPrivateWindow");
     });
@@ -30,78 +29,9 @@ document.addEventListener("DOMContentLoa
   document.getElementById("learnMore").setAttribute("href",
     RPMGetFormatURLPref("app.support.baseURL") + "private-browsing");
 
   let tpEnabled = RPMGetBoolPref(TP_PB_ENABLED_PREF);
   if (!tpEnabled) {
     document.getElementById("tpSubHeader").remove();
     document.getElementById("tpSection").remove();
   }
-
-  let searchUIEnabled = RPMGetBoolPref(PB_SEARCH_UI_ENABLED_PREF);
-  if (searchUIEnabled) {
-    setupSearchUI();
-  }
 });
-
-function setupSearchUI() {
-  // Show the new search UI and hide the old one.
-  document.documentElement.classList.remove("no-search-ui");
-  document.documentElement.classList.add("search-ui");
-
-  // Setup the private browsing myths link.
-  document.getElementById("private-browsing-myths").setAttribute("href",
-    RPMGetFormatURLPref("app.support.baseURL") + "private-browsing-myths");
-
-  // Setup the search hand-off box.
-  let btn = document.getElementById("search-handoff-button");
-  let editable = document.getElementById("fake-editable");
-  let HIDE_SEARCH_TOPIC = "HideSearch";
-  let SHOW_SEARCH_TOPIC = "ShowSearch";
-  let SEARCH_HANDOFF_TOPIC = "SearchHandoff";
-
-  function showSearch() {
-    btn.classList.remove("focused");
-    btn.classList.remove("hidden");
-    RPMRemoveMessageListener(SHOW_SEARCH_TOPIC, showSearch);
-  }
-
-  function hideSearch() {
-    btn.classList.add("hidden");
-  }
-
-  function handoffSearch(text) {
-    RPMSendAsyncMessage(SEARCH_HANDOFF_TOPIC, {text});
-    RPMAddMessageListener(SHOW_SEARCH_TOPIC, showSearch);
-    if (text) {
-      hideSearch();
-    } else {
-      btn.classList.add("focused");
-      RPMAddMessageListener(HIDE_SEARCH_TOPIC, hideSearch);
-    }
-  }
-  btn.addEventListener("focus", function() {
-    handoffSearch();
-  });
-  btn.addEventListener("click", function() {
-    handoffSearch();
-  });
-
-  // Hand-off any text that gets dropped or pasted
-  editable.addEventListener("drop", function(ev) {
-    ev.preventDefault();
-    let text = ev.dataTransfer.getData("text");
-    if (text) {
-      handoffSearch(text);
-    }
-  });
-  editable.addEventListener("paste", function(ev) {
-    ev.preventDefault();
-    handoffSearch(ev.clipboardData.getData("Text"));
-  });
-
-  // Load contentSearchUI so it sets the search engine icon for us.
-  // TODO: FIXME. We should eventually refector contentSearchUI to do only what
-  // we need and have it do the common search handoff work for
-  // about:newtab and about:privatebrowsing.
-  let input = document.getElementById("dummy-input");
-  new window.ContentSearchUIController(input, input.parentNode, "aboutprivatebrowsing", "aboutprivatebrowsing");
-}

--- a/browser/components/privatebrowsing/content/aboutPrivateBrowsing.xhtml
+++ b/browser/components/privatebrowsing/content/aboutPrivateBrowsing.xhtml
@@ -12,32 +12,31 @@
   <!ENTITY % brandDTD SYSTEM "chrome://branding/locale/brand.dtd">
   %brandDTD;
   <!ENTITY % browserDTD SYSTEM "chrome://browser/locale/browser.dtd">
   %browserDTD;
   <!ENTITY % aboutPrivateBrowsingDTD SYSTEM "chrome://browser/locale/aboutPrivateBrowsing.dtd">
   %aboutPrivateBrowsingDTD;
 ]>
 
-<html xmlns="http://www.w3.org/1999/xhtml" class="private no-search-ui">
+<html xmlns="http://www.w3.org/1999/xhtml" class="private">
   <head>
-    <meta http-equiv="Content-Security-Policy" content="default-src chrome: blob:"/>
+    <meta http-equiv="Content-Security-Policy" content="default-src chrome:"/>
     <link rel="icon" type="image/png" href="chrome://browser/skin/privatebrowsing/favicon.svg"/>
     <link rel="stylesheet" href="chrome://browser/content/aboutPrivateBrowsing.css" type="text/css" media="all"/>
     <link rel="stylesheet" href="chrome://browser/skin/privatebrowsing/aboutPrivateBrowsing.css" type="text/css" media="all"/>
     <script type="application/javascript" src="chrome://browser/content/aboutPrivateBrowsing.js"></script>
-    <script type="application/javascript" src="chrome://browser/content/contentSearchUI.js"></script>
   </head>
 
   <body dir="&locale.dir;">
     <p class="showNormal">&aboutPrivateBrowsing.notPrivate;</p>
     <button id="startPrivateBrowsing"
             class="showNormal"
             accesskey="&privatebrowsingpage.openPrivateWindow.accesskey;">&privatebrowsingpage.openPrivateWindow.label;</button>
-    <div class="showPrivate dontShowSearch container">
+    <div class="showPrivate container">
       <h1 class="title">
         <span id="title">&privateBrowsing.title;</span>
       </h1>
       <section class="section-main">
         <p>&aboutPrivateBrowsing.info.notsaved.before;<strong>&aboutPrivateBrowsing.info.notsaved.emphasize;</strong>&aboutPrivateBrowsing.info.notsaved.after;</p>
         <ul class="list-row">
           <li>&aboutPrivateBrowsing.info.visited;</li>
           <li>&aboutPrivateBrowsing.info.cookies;</li>
@@ -63,32 +62,10 @@
           <a id="startTour" class="button">&trackingProtection.startTour1;</a>
         </p>
       </section>
 
       <section class="section-main">
         <p class="about-info">&aboutPrivateBrowsing.learnMore3.before;<a id="learnMore" target="_blank">&aboutPrivateBrowsing.learnMore3.title;</a>&aboutPrivateBrowsing.learnMore3.after;</p>
       </section>
     </div>
-    <div class="showPrivate showSearch container">
-      <div class="logo-and-wordmark">
-        <div class="logo" />
-        <div class="wordmark" />
-      </div>
-      <div class="search-inner-wrapper">
-        <button id="search-handoff-button" class="search-handoff-button" title="&aboutPrivateBrowsing.search.placeholder;" tabindex="-1">
-          <div class="fake-textbox">&aboutPrivateBrowsing.search.placeholder;</div>
-          <div id="fake-editable" class="fake-editable" tabindex="-1" aria-hidden="true" contenteditable="" />
-          <div class="fake-caret" />
-        </button>
-        <input id="dummy-input" class="dummy-input" type="search" />
-      </div>
-      <div class="info">
-        <h1>&aboutPrivateBrowsing.info.title;</h1>
-        <p>
-          &aboutPrivateBrowsing.info.description;
-          <br/>
-          <a id="private-browsing-myths">&aboutPrivateBrowsing.info.myths;</a>
-        </p>
-      </div>
-    </div>
   </body>
 </html>

--- a/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_about.js
+++ b/browser/components/privatebrowsing/test/browser/browser_privatebrowsing_about.js
@@ -67,100 +67,8 @@ add_task(async function test_links() {
   await testLinkOpensUrl({ win, tab,
     elementId: "startTour",
     expectedUrl: "https://example.com/tour?variation=1",
   });
 
   await BrowserTestUtils.closeWindow(win);
 });
 
-/**
- * Tests the private-browsing-myths link in "about:privatebrowsing".
- */
-add_task(async function test_myths_link() {
-  Services.prefs.setCharPref("app.support.baseURL", "https://example.com/");
-  registerCleanupFunction(function() {
-    Services.prefs.clearUserPref("app.support.baseURL");
-  });
-
-  let { win, tab } = await openAboutPrivateBrowsing();
-
-  await testLinkOpensUrl({ win, tab,
-    elementId: "private-browsing-myths",
-    expectedUrl: "https://example.com/private-browsing-myths",
-  });
-
-  await BrowserTestUtils.closeWindow(win);
-});
-
-function urlBarHasHiddenFocus(win) {
-  return win.gURLBar.hasAttribute("focused") && win.gURLBar.classList.contains("hidden-focus");
-}
-
-function urlBarHasNormalFocus(win) {
-  return win.gURLBar.hasAttribute("focused") && !win.gURLBar.classList.contains("hidden-focus");
-}
-
-/**
- * Tests the search hand-off on character keydown in "about:privatebrowsing".
- */
-add_task(async function test_search_handoff_on_keydown() {
-  let { win, tab } = await openAboutPrivateBrowsing();
-
-  await ContentTask.spawn(tab, null, async function() {
-    let btn = content.document.getElementById("search-handoff-button");
-    btn.click();
-    ok(btn.classList.contains("focused"), "in-content search has focus styles");
-  });
-  ok(urlBarHasHiddenFocus(win), "url bar has hidden focused");
-  await new Promise(r => EventUtils.synthesizeKey("f", {}, win, r));
-  await ContentTask.spawn(tab, null, async function() {
-    ok(content.document.getElementById("search-handoff-button").classList.contains("hidden"),
-      "in-content search is hidden");
-  });
-  ok(urlBarHasNormalFocus(win), "url bar has normal focused");
-  is(win.gURLBar.value, "@google f", "url bar has search text");
-
-  // Hitting ESC should reshow the in-content search
-  await new Promise(r => EventUtils.synthesizeKey("KEY_Escape", {}, win, r));
-  await ContentTask.spawn(tab, null, async function() {
-    ok(!content.document.getElementById("search-handoff-button").classList.contains("hidden"),
-      "in-content search is not");
-  });
-
-  await BrowserTestUtils.closeWindow(win);
-});
-
-/**
- * Tests the search hand-off on composition start in "about:privatebrowsing".
- */
-add_task(async function test_search_handoff_on_composition_start() {
-  let { win, tab } = await openAboutPrivateBrowsing();
-
-  await ContentTask.spawn(tab, null, async function() {
-    content.document.getElementById("search-handoff-button").click();
-  });
-  ok(urlBarHasHiddenFocus(win), "url bar has hidden focused");
-  await new Promise(r => EventUtils.synthesizeComposition({type: "compositionstart"}, win, r));
-  ok(urlBarHasNormalFocus(win), "url bar has normal focused");
-
-  await BrowserTestUtils.closeWindow(win);
-});
-
-/**
-* Tests the search hand-off on paste in "about:privatebrowsing".
-*/
-add_task(async function test_search_handoff_on_paste() {
-  let { win, tab } = await openAboutPrivateBrowsing();
-
-  await ContentTask.spawn(tab, null, async function() {
-    content.document.getElementById("search-handoff-button").click();
-  });
-  ok(urlBarHasHiddenFocus(win), "url bar has hidden focused");
-  var helper = SpecialPowers.Cc["@mozilla.org/widget/clipboardhelper;1"]
-     .getService(SpecialPowers.Ci.nsIClipboardHelper);
-  helper.copyString("words");
-  await new Promise(r => EventUtils.synthesizeKey("v", {accelKey: true}, win, r));
-  ok(urlBarHasNormalFocus(win), "url bar has normal focused");
-  is(win.gURLBar.value, "@google words", "url bar has search text");
-
-  await BrowserTestUtils.closeWindow(win);
-});

--- a/browser/themes/shared/privatebrowsing/aboutPrivateBrowsing.css
+++ b/browser/themes/shared/privatebrowsing/aboutPrivateBrowsing.css
@@ -98,153 +98,8 @@ a.button {
   text-decoration: none;
   display: inline-block;
 }
 
 a.button:hover:active {
   color: inherit;
   background-color: #6000a1;
 }
-
-.logo-and-wordmark {
-  align-items: center;
-  display: flex;
-  justify-content: center;
-  margin-bottom: 50px;
-}
-
-.search-ui .container {
-  max-width: 768px;
-}
-
-.logo {
-  background: url("chrome://branding/content/icon128.png") no-repeat center center;
-  background-size: 97px;
-  display: inline-block;
-  height: 97px;
-  width: 97px;
-}
-
-.wordmark {
-  background: url("resource://activity-stream/data/content/assets/firefox-wordmark.svg") no-repeat center center;
-  background-size: 175px;
-  -moz-context-properties: fill;
-  display: inline-block;
-  fill: #fff;
-  height: 97px;
-  margin-inline-start: 15px;
-  width: 175px;
-}
-
-.search-inner-wrapper {
-  display: flex;
-  height: 48px;
-  margin-bottom: 64px;
-  padding: 0 22px;
-}
-
-.search-handoff-button {
-  background: #fff var(--newtab-search-icon) 12px center no-repeat;
-  background-size: 24px;
-  border: solid 1px rgba(249, 249, 250, 0.2);
-  border-radius: 3px;
-  box-shadow: 0 1px 4px 0 rgba(12, 12, 13, 0.2), 0 0 0 1px rgba(0, 0, 0, 0.15);
-  cursor: text;
-  font-size: 15px;
-  margin: 0;
-  padding: 0;
-  padding-inline-end: 48px;
-  padding-inline-start: 46px;
-  position: relative;
-  opacity: 1;
-  transition: opacity 500ms;
-  width: 100%;
-}
-
-.search-handoff-button.focused {
-  border: solid 1px #0060df;
-  box-shadow: 0 0 0 1px #0060df, 0 0 0 4px rgba(0, 96, 223, 0.3);
-}
-
-.search-handoff-button.hidden {
-  opacity: 0;
-  visibility: hidden;
-}
-
-.search-handoff-button:dir(rtl) {
-  background-position-x: right 12px;
-}
-
-.search-inner-wrapper .search-handoff-button:hover {
-  background-color: #fff;
-}
-
-.search-handoff-button.focused .fake-caret {
-  display: block;
-}
-
-.fake-editable:focus {
-  outline: none;
-  caret-color: transparent;
-}
-
-.fake-editable {
-  color: transparent;
-  position: absolute;
-  top: 0;
-  left: 0;
-  right: 0;
-  bottom: 0;
-}
-
-.fake-textbox {
-  color: rgb(12, 12, 13);
-  opacity: 0.54;
-  text-align: start;
-}
-
-@keyframes caret-animation {
-  to {
-    visibility: hidden;
-  }
-}
-
-.fake-caret {
-  animation: caret-animation 1.3s steps(5, start) infinite;
-  background: rgb(12, 12, 13);
-  display: none;
-  inset-inline-start: 47px;
-  height: 17px;
-  position: absolute;
-  top: 16px;
-  width: 1px;
-}
-
-.dummy-input {
-  display: none;
-}
-
-.info {
-  background-color: rgba(0, 0, 0, 0.2);
-  background-image: url("chrome://browser/skin/privatebrowsing/private-browsing.svg");
-  background-position: left 32px top 20px;
-  background-repeat: no-repeat;
-  background-size: 32px;
-  border-radius: 6px;
-  letter-spacing: -0.2px;
-  padding: 20px;
-  padding-inline-start: 76px;
-}
-
-.info:dir(rtl) {
-  background-position: right 32px top 20px;
-}
-
-.info h1 {
-  font-size: 18px;
-  font-weight: bold;
-  line-height: 28px;
-}
-
-.info p {
-  font-size: 15px;
-  line-height: 25px;
-}

--- a/toolkit/components/remotepagemanager/MessagePort.jsm
+++ b/toolkit/components/remotepagemanager/MessagePort.jsm
@@ -20,18 +20,17 @@ ChromeUtils.defineModuleGetter(this, "Pr
  * whitelisted within AsyncPrefs.jsm.
  */
 let RPMAccessManager = {
   accessMap: {
     "about:privatebrowsing": {
       // "sendAsyncMessage": handled within AboutPrivateBrowsingHandler.jsm
       // "setBoolPref": handled within AsyncPrefs.jsm and uses the pref
       //                ["privacy.trackingprotection.pbmode.enabled"],
-      "getBoolPref": ["privacy.trackingprotection.pbmode.enabled",
-                      "browser.privatebrowsing.searchUI"],
+      "getBoolPref": ["privacy.trackingprotection.pbmode.enabled"],
       "getFormatURLPref": ["privacy.trackingprotection.introURL",
                            "app.support.baseURL"],
       "isWindowPrivate": ["yes"],
     },
   },
 
   checkAllowAccess(aPrincipal, aFeature, aValue) {
     // if there is no content principal; deny access