deleted file mode 100644
--- a/browser/base/content/contentSearchHandoffUI.js
+++ /dev/null
@@ -1,79 +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/. */
-
-"use strict";
-
-function ContentSearchHandoffUIController() {
-  this._isPrivateWindow = false;
-  this._engineIcon = null;
-
-  window.addEventListener("ContentSearchService", this);
-  this._sendMsg("GetEngine");
-}
-
-ContentSearchHandoffUIController.prototype = {
-  handleEvent(event) {
-    let methodName = "_onMsg" + event.detail.type;
-    if (methodName in this) {
-      this[methodName](event.detail.data);
-    }
-  },
-
-  _onMsgEngine({ isPrivateWindow, engine }) {
-    this._isPrivateWindow = isPrivateWindow;
-    this._updateEngineIcon(engine);
-  },
-
-  _onMsgCurrentEngine(engine) {
-    if (!this._isPrivateWindow) {
-      this._updateEngineIcon(engine);
-    }
-  },
-
-  _onMsgCurrentPrivateEngine(engine) {
-    if (this._isPrivateWindow) {
-      this._updateEngineIcon(engine);
-    }
-  },
-
-  _updateEngineIcon(engine) {
-    if (this._engineIcon) {
-      URL.revokeObjectURL(this._engineIcon);
-    }
-
-    if (engine.iconData) {
-      this._engineIcon = this._getFaviconURIFromIconData(engine.iconData);
-    } else {
-      this._engineIcon = "chrome://mozapps/skin/places/defaultFavicon.svg";
-    }
-
-    document.body.style.setProperty(
-      "--newtab-search-icon",
-      "url(" + this._engineIcon + ")"
-    );
-  },
-
-  // If the favicon is an array buffer, convert it into a Blob URI.
-  // Otherwise just return the plain URI.
-  _getFaviconURIFromIconData(data) {
-    if (typeof data === "string") {
-      return data;
-    }
-
-    // If typeof(data) != "string", we assume it's an ArrayBuffer
-    let blob = new Blob([data]);
-    return URL.createObjectURL(blob);
-  },
-
-  _sendMsg(type, data = null) {
-    dispatchEvent(
-      new CustomEvent("ContentSearchClient", {
-        detail: {
-          type,
-          data,
-        },
-      })
-    );
-  },
-};

--- a/browser/base/jar.mn
+++ b/browser/base/jar.mn
@@ -89,17 +89,16 @@ browser.jar:
         content/browser/static-robot.png              (content/static-robot.png)
         content/browser/safeMode.css                  (content/safeMode.css)
         content/browser/safeMode.js                   (content/safeMode.js)
         content/browser/safeMode.xhtml                (content/safeMode.xhtml)
         content/browser/sanitize.xhtml                (content/sanitize.xhtml)
         content/browser/sanitizeDialog.js             (content/sanitizeDialog.js)
         content/browser/sanitizeDialog.css            (content/sanitizeDialog.css)
         content/browser/contentSearchUI.js            (content/contentSearchUI.js)
-        content/browser/contentSearchHandoffUI.js     (content/contentSearchHandoffUI.js)
         content/browser/contentSearchUI.css           (content/contentSearchUI.css)
         content/browser/tabbrowser.css                (content/tabbrowser.css)
         content/browser/tabbrowser.js                 (content/tabbrowser.js)
         content/browser/tabbrowser-tab.js             (content/tabbrowser-tab.js)
         content/browser/tabbrowser-tabs.js            (content/tabbrowser-tabs.js)
         content/browser/utilityOverlay.js             (content/utilityOverlay.js)
         content/browser/webext-panels.js              (content/webext-panels.js)
 *       content/browser/webext-panels.xhtml           (content/webext-panels.xhtml)

--- a/browser/components/newtab/bin/render-activity-stream-html.js
+++ b/browser/components/newtab/bin/render-activity-stream-html.js
@@ -23,17 +23,16 @@ const DEFAULT_OPTIONS = {
  *         {bool} options.debug         Should we use dev versions of JS libraries?
  *         {bool} options.noscripts     Should we include scripts in the prerendered files?
  * @return {str}         An HTML document as a string
  */
 function templateHTML(options) {
   const debugString = options.debug ? "-dev" : "";
   const scripts = [
     "chrome://browser/content/contentSearchUI.js",
-    "chrome://browser/content/contentSearchHandoffUI.js",
     "chrome://browser/content/contentTheme.js",
     `${options.baseUrl}vendor/react${debugString}.js`,
     `${options.baseUrl}vendor/react-dom${debugString}.js`,
     `${options.baseUrl}vendor/prop-types.js`,
     `${options.baseUrl}vendor/redux.js`,
     `${options.baseUrl}vendor/react-redux.js`,
     `${options.baseUrl}vendor/react-transition-group.js`,
     `${options.baseUrl}data/content/activity-stream.bundle.js`,

--- a/browser/components/newtab/content-src/components/Search/Search.jsx
+++ b/browser/components/newtab/content-src/components/Search/Search.jsx
@@ -1,29 +1,28 @@
 /* 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/. */
 
-/* globals ContentSearchUIController, ContentSearchHandoffUIController */
+/* globals ContentSearchUIController */
 "use strict";
 
 import { actionCreators as ac, actionTypes as at } from "common/Actions.jsm";
 import { connect } from "react-redux";
 import { IS_NEWTAB } from "content-src/lib/constants";
 import React from "react";
 
 export class _Search extends React.PureComponent {
   constructor(props) {
     super(props);
     this.onSearchClick = this.onSearchClick.bind(this);
     this.onSearchHandoffClick = this.onSearchHandoffClick.bind(this);
     this.onSearchHandoffPaste = this.onSearchHandoffPaste.bind(this);
     this.onSearchHandoffDrop = this.onSearchHandoffDrop.bind(this);
     this.onInputMount = this.onInputMount.bind(this);
-    this.onInputMountHandoff = this.onInputMountHandoff.bind(this);
     this.onSearchHandoffButtonMount = this.onSearchHandoffButtonMount.bind(
       this
     );
   }
 
   handleEvent(event) {
     // Also track search events with our own telemetry
     if (event.detail.type === "Search") {
@@ -99,24 +98,16 @@ export class _Search extends React.PureC
       );
       addEventListener("ContentSearchClient", this);
     } else {
       window.gContentSearchController = null;
       removeEventListener("ContentSearchClient", this);
     }
   }
 
-  onInputMountHandoff(input) {
-    if (input) {
-      // The handoff UI controller helps usset the search icon and reacts to
-      // changes to default engine to keep everything in sync.
-      this._handoffSearchController = new ContentSearchHandoffUIController();
-    }
-  }
-
   onSearchHandoffButtonMount(button) {
     // Keep a reference to the button for use during "paste" event handling.
     this._searchHandoffButton = button;
   }
 
   /*
    * Do not change the ID on the input field, as legacy newtab code
    * specifically looks for the id 'newtab-search-text' on input fields
@@ -171,20 +162,28 @@ export class _Search extends React.PureC
               />
               <input
                 type="search"
                 className="fake-editable"
                 tabIndex="-1"
                 aria-hidden="true"
                 onDrop={this.onSearchHandoffDrop}
                 onPaste={this.onSearchHandoffPaste}
-                ref={this.onInputMountHandoff}
               />
               <div className="fake-caret" />
             </button>
+            {/*
+            This dummy and hidden input below is so we can load ContentSearchUIController.
+            Why? It sets --newtab-search-icon for us and it isn't trivial to port over.
+          */}
+            <input
+              type="search"
+              style={{ display: "none" }}
+              ref={this.onInputMount}
+            />
           </div>
         )}
       </div>
     );
   }
 }
 
 export const Search = connect()(_Search);

--- a/browser/components/newtab/data/content/activity-stream.bundle.js
+++ b/browser/components/newtab/data/content/activity-stream.bundle.js
@@ -10281,32 +10281,31 @@ const TopSites = Object(react_redux__WEB
 /* harmony import */ var react_redux__WEBPACK_IMPORTED_MODULE_1___default = /*#__PURE__*/__webpack_require__.n(react_redux__WEBPACK_IMPORTED_MODULE_1__);
 /* harmony import */ var content_src_lib_constants__WEBPACK_IMPORTED_MODULE_2__ = __webpack_require__(11);
 /* harmony import */ var react__WEBPACK_IMPORTED_MODULE_3__ = __webpack_require__(9);
 /* harmony import */ var react__WEBPACK_IMPORTED_MODULE_3___default = /*#__PURE__*/__webpack_require__.n(react__WEBPACK_IMPORTED_MODULE_3__);
 /* 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/. */
 
-/* globals ContentSearchUIController, ContentSearchHandoffUIController */
+/* globals ContentSearchUIController */
 
 
 
 
 
 
 class _Search extends react__WEBPACK_IMPORTED_MODULE_3___default.a.PureComponent {
   constructor(props) {
     super(props);
     this.onSearchClick = this.onSearchClick.bind(this);
     this.onSearchHandoffClick = this.onSearchHandoffClick.bind(this);
     this.onSearchHandoffPaste = this.onSearchHandoffPaste.bind(this);
     this.onSearchHandoffDrop = this.onSearchHandoffDrop.bind(this);
     this.onInputMount = this.onInputMount.bind(this);
-    this.onInputMountHandoff = this.onInputMountHandoff.bind(this);
     this.onSearchHandoffButtonMount = this.onSearchHandoffButtonMount.bind(this);
   }
 
   handleEvent(event) {
     // Also track search events with our own telemetry
     if (event.detail.type === "Search") {
       this.props.dispatch(common_Actions_jsm__WEBPACK_IMPORTED_MODULE_0__["actionCreators"].UserEvent({
         event: "SEARCH"
@@ -10386,24 +10385,16 @@ class _Search extends react__WEBPACK_IMP
       window.gContentSearchController = new ContentSearchUIController(input, input.parentNode, healthReportKey, searchSource);
       addEventListener("ContentSearchClient", this);
     } else {
       window.gContentSearchController = null;
       removeEventListener("ContentSearchClient", this);
     }
   }
 
-  onInputMountHandoff(input) {
-    if (input) {
-      // The handoff UI controller helps usset the search icon and reacts to
-      // changes to default engine to keep everything in sync.
-      this._handoffSearchController = new ContentSearchHandoffUIController();
-    }
-  }
-
   onSearchHandoffButtonMount(button) {
     // Keep a reference to the button for use during "paste" event handling.
     this._searchHandoffButton = button;
   }
   /*
    * Do not change the ID on the input field, as legacy newtab code
    * specifically looks for the id 'newtab-search-text' on input fields
    * in order to execute searches in various tests
@@ -10445,21 +10436,26 @@ class _Search extends react__WEBPACK_IMP
       className: "fake-textbox",
       "data-l10n-id": "newtab-search-box-search-the-web-text"
     }), react__WEBPACK_IMPORTED_MODULE_3___default.a.createElement("input", {
       type: "search",
       className: "fake-editable",
       tabIndex: "-1",
       "aria-hidden": "true",
       onDrop: this.onSearchHandoffDrop,
-      onPaste: this.onSearchHandoffPaste,
-      ref: this.onInputMountHandoff
+      onPaste: this.onSearchHandoffPaste
     }), react__WEBPACK_IMPORTED_MODULE_3___default.a.createElement("div", {
       className: "fake-caret"
-    }))));
+    })), react__WEBPACK_IMPORTED_MODULE_3___default.a.createElement("input", {
+      type: "search",
+      style: {
+        display: "none"
+      },
+      ref: this.onInputMount
+    })));
   }
 
 }
 const Search = Object(react_redux__WEBPACK_IMPORTED_MODULE_1__["connect"])()(_Search);
 
 /***/ }),
 /* 77 */
 /***/ (function(module, __webpack_exports__, __webpack_require__) {

--- a/browser/components/newtab/prerendered/activity-stream-debug.html
+++ b/browser/components/newtab/prerendered/activity-stream-debug.html
@@ -15,17 +15,16 @@
     <link rel="stylesheet" href="chrome://browser/content/contentSearchUI.css" />
     <link rel="stylesheet" href="resource://activity-stream/css/activity-stream.css" />
   </head>
   <body class="activity-stream">
     <div id="header-asrouter-container" role="presentation"></div>
     <div id="root"></div>
     <div id="footer-asrouter-container" role="presentation"></div>
     <script src="chrome://browser/content/contentSearchUI.js"></script>
-    <script src="chrome://browser/content/contentSearchHandoffUI.js"></script>
     <script src="chrome://browser/content/contentTheme.js"></script>
     <script src="resource://activity-stream/vendor/react-dev.js"></script>
     <script src="resource://activity-stream/vendor/react-dom-dev.js"></script>
     <script src="resource://activity-stream/vendor/prop-types.js"></script>
     <script src="resource://activity-stream/vendor/redux.js"></script>
     <script src="resource://activity-stream/vendor/react-redux.js"></script>
     <script src="resource://activity-stream/vendor/react-transition-group.js"></script>
     <script src="resource://activity-stream/data/content/activity-stream.bundle.js"></script>

--- a/browser/components/newtab/prerendered/activity-stream.html
+++ b/browser/components/newtab/prerendered/activity-stream.html
@@ -15,17 +15,16 @@
     <link rel="stylesheet" href="chrome://browser/content/contentSearchUI.css" />
     <link rel="stylesheet" href="resource://activity-stream/css/activity-stream.css" />
   </head>
   <body class="activity-stream">
     <div id="header-asrouter-container" role="presentation"></div>
     <div id="root"></div>
     <div id="footer-asrouter-container" role="presentation"></div>
     <script src="chrome://browser/content/contentSearchUI.js"></script>
-    <script src="chrome://browser/content/contentSearchHandoffUI.js"></script>
     <script src="chrome://browser/content/contentTheme.js"></script>
     <script src="resource://activity-stream/vendor/react.js"></script>
     <script src="resource://activity-stream/vendor/react-dom.js"></script>
     <script src="resource://activity-stream/vendor/prop-types.js"></script>
     <script src="resource://activity-stream/vendor/redux.js"></script>
     <script src="resource://activity-stream/vendor/react-redux.js"></script>
     <script src="resource://activity-stream/vendor/react-transition-group.js"></script>
     <script src="resource://activity-stream/data/content/activity-stream.bundle.js"></script>

--- a/browser/components/privatebrowsing/content/aboutPrivateBrowsing.js
+++ b/browser/components/privatebrowsing/content/aboutPrivateBrowsing.js
@@ -113,10 +113,19 @@ document.addEventListener("DOMContentLoa
     }
   });
   editable.addEventListener("paste", function(ev) {
     ev.preventDefault();
     handoffSearch(ev.clipboardData.getData("Text"));
   });
 
   // Load contentSearchUI so it sets the search engine icon for us.
-  new window.ContentSearchHandoffUIController();
+  // 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
@@ -10,17 +10,17 @@
   <head>
     <meta http-equiv="Content-Security-Policy" content="default-src chrome: blob:; object-src 'none'"/>
     <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"/>
     <link rel="localization" href="branding/brand.ftl"/>
     <link rel="localization" href="browser/aboutPrivateBrowsing.ftl"/>
     <script src="chrome://browser/content/aboutPrivateBrowsing.js"></script>
-    <script src="chrome://browser/content/contentSearchHandoffUI.js"></script>
+    <script src="chrome://browser/content/contentSearchUI.js"></script>
   </head>
 
   <body>
     <p class="showNormal" data-l10n-id="about-private-browsing-not-private"></p>
     <button id="startPrivateBrowsing"
             class="showNormal" data-l10n-id="privatebrowsingpage-open-private-window-label"></button>
     <div id="search-banner" class="search-banner"
          hidden="true">
@@ -45,16 +45,17 @@
         <div class="wordmark" />
       </div>
       <div class="search-inner-wrapper">
         <button id="search-handoff-button" class="search-handoff-button" tabindex="-1" data-l10n-id="about-private-browsing">
           <div class="fake-textbox" data-l10n-id="about-private-browsing-search-placeholder"></div>
           <input id="fake-editable" class="fake-editable" tabindex="-1" aria-hidden="true" />
           <div class="fake-caret" />
         </button>
+        <input id="dummy-input" class="dummy-input" type="search" />
       </div>
       <div class="info">
         <h1 data-l10n-id="about-private-browsing-info-title"></h1>
         <p data-l10n-id="about-private-browsing-info-description"></p>
         <a id="private-browsing-myths" data-l10n-id="about-private-browsing-info-myths"></a>
       </div>
     </div>
   </body>

--- a/browser/modules/ContentSearch.jsm
+++ b/browser/modules/ContentSearch.jsm
@@ -448,27 +448,16 @@ var ContentSearch = {
   },
 
   _onMessageGetState(msg, data) {
     return this.currentStateObj(msg.target.ownerGlobal).then(state => {
       this._reply(msg, "State", state);
     });
   },
 
-  _onMessageGetEngine(msg, data) {
-    return this.currentStateObj(msg.target.ownerGlobal).then(state => {
-      this._reply(msg, "Engine", {
-        isPrivateWindow: state.isPrivateWindow,
-        engine: state.isPrivateWindow
-          ? state.currentPrivateEngine
-          : state.currentEngine,
-      });
-    });
-  },
-
   _onMessageGetStrings(msg, data) {
     this._reply(msg, "Strings", this.searchSuggestionUIStrings);
   },
 
   _onMessageSearch(msg, data) {
     this.performSearch(msg, data);
   },
 

--- a/browser/themes/shared/privatebrowsing/aboutPrivateBrowsing.css
+++ b/browser/themes/shared/privatebrowsing/aboutPrivateBrowsing.css
@@ -158,16 +158,20 @@ p {
   display: none;
   inset-inline-start: 47px;
   height: 17px;
   position: absolute;
   top: 16px;
   width: 1px;
 }
 
+.dummy-input {
+  display: none;
+}
+
 .search-banner {
   width: 100%;
   background-color: var(--in-content-banner-background);
   color: var(--in-content-banner-text-color);
 }
 
 .banner-body {
   margin: auto;