--- a/browser/components/extensions/ext-browser.json
+++ b/browser/components/extensions/ext-browser.json
@@ -138,24 +138,16 @@
   "geckoProfiler": {
     "url": "chrome://browser/content/parent/ext-geckoProfiler.js",
     "schema": "chrome://browser/content/schemas/geckoProfiler.json",
     "scopes": ["addon_parent"],
     "paths": [
       ["geckoProfiler"]
     ]
   },
-  "search": {
-    "url": "chrome://browser/content/parent/ext-search.js",
-    "schema": "chrome://browser/content/schemas/search.json",
-    "scopes": ["addon_parent"],
-    "paths": [
-      ["search"]
-    ]
-  },
   "sessions": {
     "url": "chrome://browser/content/parent/ext-sessions.js",
     "schema": "chrome://browser/content/schemas/sessions.json",
     "scopes": ["addon_parent"],
     "paths": [
       ["sessions"]
     ]
   },

--- a/browser/components/extensions/jar.mn
+++ b/browser/components/extensions/jar.mn
@@ -25,17 +25,16 @@ browser.jar:
     content/browser/parent/ext-devtools-panels.js (parent/ext-devtools-panels.js)
     content/browser/parent/ext-find.js (parent/ext-find.js)
     content/browser/parent/ext-geckoProfiler.js (parent/ext-geckoProfiler.js)
     content/browser/parent/ext-history.js (parent/ext-history.js)
     content/browser/parent/ext-menus.js (parent/ext-menus.js)
     content/browser/parent/ext-omnibox.js (parent/ext-omnibox.js)
     content/browser/parent/ext-pageAction.js (parent/ext-pageAction.js)
     content/browser/parent/ext-pkcs11.js (parent/ext-pkcs11.js)
-    content/browser/parent/ext-search.js (parent/ext-search.js)
     content/browser/parent/ext-sessions.js (parent/ext-sessions.js)
     content/browser/parent/ext-sidebarAction.js (parent/ext-sidebarAction.js)
     content/browser/parent/ext-tabs.js (parent/ext-tabs.js)
     content/browser/parent/ext-url-overrides.js (parent/ext-url-overrides.js)
     content/browser/parent/ext-windows.js (parent/ext-windows.js)
     content/browser/child/ext-browser.js (child/ext-browser.js)
     content/browser/child/ext-devtools-inspectedWindow.js (child/ext-devtools-inspectedWindow.js)
     content/browser/child/ext-devtools-network.js (child/ext-devtools-network.js)

--- a/browser/components/extensions/parent/.eslintrc.js
+++ b/browser/components/extensions/parent/.eslintrc.js
@@ -16,16 +16,15 @@ module.exports = {
     "getToolboxEvalOptions": true,
     "isContainerCookieStoreId": true,
     "isPrivateCookieStoreId": true,
     "isValidCookieStoreId": true,
     "makeWidgetId": true,
     "openOptionsPage": true,
     "pageActionFor": true,
     "replaceUrlInTab": true,
-    "searchInitialized": true,
     "sidebarActionFor": true,
     "tabGetSender": true,
     "tabTracker": true,
     "waitForTabLoaded": true,
     "windowTracker": true,
   },
 };

--- a/browser/components/extensions/parent/ext-browser.js
+++ b/browser/components/extensions/parent/ext-browser.js
@@ -218,26 +218,16 @@ global.TabContext = class extends EventE
    */
   shutdown() {
     windowTracker.removeListener("progress", this);
     windowTracker.removeListener("TabSelect", this);
     tabTracker.off("tab-adopted", this.tabAdopted);
   }
 };
 
-// This promise is used to wait for the search service to be initialized.
-// None of the code in the WebExtension modules requests that initialization.
-// It is assumed that it is started at some point. If tests start to fail
-// because this promise never resolves, that's likely the cause.
-XPCOMUtils.defineLazyGetter(global, "searchInitialized", () => {
-  if (Services.search.isInitialized) {
-    return Promise.resolve();
-  }
-  return ExtensionUtils.promiseObserved("browser-search-service", (_, data) => data == "init-complete");
-});
 
 class WindowTracker extends WindowTrackerBase {
   addProgressListener(window, listener) {
     window.gBrowser.addTabsProgressListener(listener);
   }
 
   removeProgressListener(window, listener) {
     window.gBrowser.removeTabsProgressListener(listener);

--- a/browser/components/extensions/parent/ext-chrome-settings-overrides.js
+++ b/browser/components/extensions/parent/ext-chrome-settings-overrides.js
@@ -15,16 +15,37 @@ const DEFAULT_SEARCH_STORE_TYPE = "defau
 const DEFAULT_SEARCH_SETTING_NAME = "defaultSearch";
 const ENGINE_ADDED_SETTING_NAME = "engineAdded";
 
 const HOMEPAGE_PREF = "browser.startup.homepage";
 const HOMEPAGE_CONFIRMED_TYPE = "homepageNotification";
 const HOMEPAGE_SETTING_TYPE = "prefs";
 const HOMEPAGE_SETTING_NAME = "homepage_override";
 
+// This promise is used to wait for the search service to be initialized.
+// None of the code in this module requests that initialization. It is assumed
+// that it is started at some point. If tests start to fail because this
+// promise never resolves, that's likely the cause.
+const searchInitialized = () => {
+  if (Services.search.isInitialized) {
+    return;
+  }
+  return new Promise(resolve => {
+    const SEARCH_SERVICE_TOPIC = "browser-search-service";
+    Services.obs.addObserver(function observer(subject, topic, data) {
+      if (data != "init-complete") {
+        return;
+      }
+
+      Services.obs.removeObserver(observer, SEARCH_SERVICE_TOPIC);
+      resolve();
+    }, SEARCH_SERVICE_TOPIC);
+  });
+};
+
 XPCOMUtils.defineLazyGetter(this, "homepagePopup", () => {
   return new ExtensionControlledPopup({
     confirmedType: HOMEPAGE_CONFIRMED_TYPE,
     observerTopic: "browser-open-homepage-start",
     popupnotificationId: "extension-homepage-notification",
     settingType: HOMEPAGE_SETTING_TYPE,
     settingKey: HOMEPAGE_SETTING_NAME,
     descriptionId: "extension-homepage-notification-description",
@@ -109,17 +130,17 @@ this.chrome_settings_overrides = class e
 
   static async removeEngine(id) {
     await ExtensionSettingsStore.initialize();
     let item = await ExtensionSettingsStore.getSetting(
       DEFAULT_SEARCH_STORE_TYPE, ENGINE_ADDED_SETTING_NAME, id);
     if (item) {
       ExtensionSettingsStore.removeSetting(
         id, DEFAULT_SEARCH_STORE_TYPE, ENGINE_ADDED_SETTING_NAME);
-      await searchInitialized;
+      await searchInitialized();
       let engine = Services.search.getEngineByName(item.value);
       try {
         Services.search.removeEngine(engine);
       } catch (e) {
         Cu.reportError(e);
       }
     }
   }
@@ -185,17 +206,17 @@ this.chrome_settings_overrides = class e
         close: () => {
           if (extension.shutdownReason == "ADDON_DISABLE") {
             homepagePopup.clearConfirmation(extension.id);
           }
         },
       });
     }
     if (manifest.chrome_settings_overrides.search_provider) {
-      await searchInitialized;
+      await searchInitialized();
       extension.callOnClose({
         close: () => {
           if (extension.shutdownReason == "ADDON_DISABLE") {
             chrome_settings_overrides.processDefaultSearchSetting("disable", extension.id);
             chrome_settings_overrides.removeEngine(extension.id);
           }
         },
       });

deleted file mode 100644
--- a/browser/components/extensions/parent/ext-search.js
+++ /dev/null
@@ -1,97 +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/. */
-
-/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* vim: set sts=2 sw=2 et tw=80: */
-
-"use strict";
-
-ChromeUtils.defineModuleGetter(this, "Services",
-                               "resource://gre/modules/Services.jsm");
-
-XPCOMUtils.defineLazyPreferenceGetter(this, "searchLoadInBackground",
-                                      "browser.search.context.loadInBackground");
-
-Cu.importGlobalProperties(["fetch", "btoa"]);
-
-var {
-  ExtensionError,
-} = ExtensionUtils;
-
-async function getDataURI(resourceURI) {
-  let response = await fetch(resourceURI);
-  let buffer = await response.arrayBuffer();
-  // Remove charset from content type
-  let contentType = response.headers.get("content-type").split(",");
-  let bytes = new Uint8Array(buffer);
-  let str = String.fromCharCode.apply(null, bytes);
-  return `data:${contentType[0]};base64,${btoa(str)}`;
-}
-
-this.search = class extends ExtensionAPI {
-  getAPI(context) {
-    return {
-      search: {
-        async get() {
-          await searchInitialized;
-          let engines = Services.search.getEngines();
-          let visibleEngines = engines.filter(engine => !engine.hidden);
-          return Promise.all(visibleEngines.map(async engine => {
-            let favicon_url = null;
-            if (engine.iconURI) {
-              if (engine.iconURI.spec.startsWith("resource:") ||
-                  engine.iconURI.spec.startsWith("chrome:")) {
-                // Convert internal URLs to data URLs
-                favicon_url = await getDataURI(engine.iconURI.spec);
-              } else {
-                favicon_url = engine.iconURI.spec;
-              }
-            }
-
-            return {
-              name: engine.name,
-              is_default: engine === Services.search.currentEngine,
-              alias: engine.alias,
-              favicon_url,
-            };
-          }));
-        },
-
-        async search(name, searchTerms, tabId) {
-          await searchInitialized;
-          let engine = Services.search.getEngineByName(name);
-          if (!engine) {
-            throw new ExtensionError(`${name} was not found`);
-          }
-          let submission = engine.getSubmission(searchTerms, null, "webextension");
-          let options = {
-            postData: submission.postData,
-            triggeringPrincipal: context.principal,
-          };
-          if (tabId === null) {
-            let browser = context.pendingEventBrowser || context.xulBrowser;
-            let {gBrowser} = browser.ownerGlobal;
-            if (!gBrowser || !gBrowser.addTab) {
-              // In some cases (about:addons, sidebar, maybe others), we need
-              // to go up one more level.
-              browser = browser.ownerDocument.docShell.chromeEventHandler;
-
-              ({gBrowser} = browser.ownerGlobal);
-            }
-            if (!gBrowser || !gBrowser.addTab) {
-              throw new ExtensionError("Unable to locate a browser.");
-            }
-            let nativeTab = gBrowser.addTab(submission.uri.spec, options);
-            if (!searchLoadInBackground) {
-              gBrowser.selectedTab = nativeTab;
-            }
-          } else {
-            let tab = tabTracker.getTab(tabId);
-            tab.linkedBrowser.loadURI(submission.uri.spec, options);
-          }
-        },
-      },
-    };
-  }
-};

--- a/browser/components/extensions/schemas/jar.mn
+++ b/browser/components/extensions/schemas/jar.mn
@@ -15,14 +15,13 @@ browser.jar:
     content/browser/schemas/find.json
     content/browser/schemas/geckoProfiler.json
     content/browser/schemas/history.json
     content/browser/schemas/menus.json
     content/browser/schemas/menus_internal.json
     content/browser/schemas/omnibox.json
     content/browser/schemas/page_action.json
     content/browser/schemas/pkcs11.json
-    content/browser/schemas/search.json
     content/browser/schemas/sessions.json
     content/browser/schemas/sidebar_action.json
     content/browser/schemas/tabs.json
     content/browser/schemas/url_overrides.json
     content/browser/schemas/windows.json

deleted file mode 100644
--- a/browser/components/extensions/schemas/search.json
+++ /dev/null
@@ -1,64 +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/. */
-
-[
-  {
-    "namespace": "search",
-    "description": "Use browser.search to interact with search engines.",
-    "types": [
-      {
-        "id": "SearchEngine",
-        "type": "object",
-        "description": "An object encapsulating a search engine",
-        "properties": {
-          "name": {
-            "type": "string"
-          },
-          "is_default": {
-            "type": "boolean"
-          },
-          "alias": {
-            "type": "string",
-            "optional": true
-          },
-          "favicon_url": {
-            "type": "string",
-            "optional": true,
-            "format": "url"
-          }
-        }
-      }
-    ],
-    "functions": [
-      {
-        "name": "get",
-        "type": "function",
-        "description": "Gets a list of search engines.",
-        "async": true,
-        "parameters": []
-      },
-      {
-        "name": "search",
-        "type": "function",
-        "requireUserInput": true,
-        "description": "Perform a search.",
-        "parameters": [
-          {
-            "name": "engineName",
-            "type": "string"
-          },
-          {
-            "name": "searchTerms",
-            "type": "string"
-          },
-          {
-            "type": "integer",
-            "name": "tabId",
-            "optional": true
-          }
-        ]
-      }
-    ]
-  }
-]

--- a/browser/components/extensions/test/browser/browser-common.ini
+++ b/browser/components/extensions/test/browser/browser-common.ini
@@ -129,17 +129,16 @@ skip-if = (verify && debug && (os == 'ma
 disabled = bug 1438663
 [browser_ext_popup_sendMessage.js]
 [browser_ext_popup_shutdown.js]
 [browser_ext_port_disconnect_on_crash.js]
 skip-if = !e10s || !crashreporter # the tab's process is killed during the test. Without e10s the parent process would die too.
 [browser_ext_port_disconnect_on_window_close.js]
 [browser_ext_runtime_openOptionsPage.js]
 [browser_ext_runtime_openOptionsPage_uninstall.js]
-[browser_ext_search.js]
 [browser_ext_runtime_setUninstallURL.js]
 [browser_ext_sessions_forgetClosedTab.js]
 [browser_ext_sessions_forgetClosedWindow.js]
 [browser_ext_sessions_getRecentlyClosed.js]
 [browser_ext_sessions_getRecentlyClosed_private.js]
 [browser_ext_sessions_getRecentlyClosed_tabs.js]
 [browser_ext_sessions_restore.js]
 [browser_ext_sessions_restoreTab.js]

deleted file mode 100644
--- a/browser/components/extensions/test/browser/browser_ext_search.js
+++ /dev/null
@@ -1,93 +0,0 @@
-/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* vim: set sts=2 sw=2 et tw=80: */
-"use strict";
-
-add_task(async function test_search() {
-  const TEST_ID = "test_search@tests.mozilla.com";
-  const SEARCH_TERM = "test";
-  const SEARCH_URL = "https://localhost/?q={searchTerms}";
-
-  async function background() {
-    await browser.tabs.create({url: "about:blank"});
-    let engines = await browser.search.get();
-    browser.test.sendMessage("engines", engines);
-    browser.browserAction.onClicked.addListener(tab => {
-      browser.tabs.onUpdated.addListener(async function(tabId, info, changedTab) {
-        if (tabId == tab.id && info.status === "complete" &&
-            changedTab.url != "about:blank") {
-          await browser.tabs.remove(tabId);
-          browser.test.sendMessage("searchLoaded", changedTab.url);
-        }
-      });
-      browser.search.search("Search Test", "test", tab.id); // Can't use SEARCH_TERM here
-    });
-  }
-
-  let extension = ExtensionTestUtils.loadExtension({
-    manifest: {
-      permissions: ["tabs"],
-      name: TEST_ID,
-      "browser_action": {},
-      "chrome_settings_overrides": {
-        "search_provider": {
-          "name": "Search Test",
-          "search_url": SEARCH_URL,
-        },
-      },
-    },
-    background,
-    useAddonManager: "temporary",
-  });
-  await extension.startup();
-
-  let addonEngines = await extension.awaitMessage("engines");
-  let engines = Services.search.getEngines().filter(engine => !engine.hidden);
-  is(addonEngines.length, engines.length, "Engine lengths are the same.");
-  let defaultEngine = addonEngines.filter(engine => engine.is_default === true);
-  is(defaultEngine.length, 1, "One default engine");
-  is(defaultEngine[0].name, Services.search.currentEngine.name, "Default engine is correct");
-  await clickBrowserAction(extension);
-  let url = await extension.awaitMessage("searchLoaded");
-  is(url, SEARCH_URL.replace("{searchTerms}", SEARCH_TERM), "Loaded page matches search");
-  await extension.unload();
-});
-
-add_task(async function test_search_notab() {
-  const TEST_ID = "test_search@tests.mozilla.com";
-  const SEARCH_TERM = "test";
-  const SEARCH_URL = "https://localhost/?q={searchTerms}";
-
-  async function background() {
-    browser.browserAction.onClicked.addListener(_ => {
-      browser.tabs.onUpdated.addListener(async (tabId, info, changedTab) => {
-        if (info.status === "complete") {
-          await browser.tabs.remove(tabId);
-          browser.test.sendMessage("searchLoaded", changedTab.url);
-        }
-      });
-      browser.search.search("Search Test", "test"); // Can't use SEARCH_TERM here
-    });
-  }
-
-  let extension = ExtensionTestUtils.loadExtension({
-    manifest: {
-      permissions: ["tabs"],
-      name: TEST_ID,
-      "browser_action": {},
-      "chrome_settings_overrides": {
-        "search_provider": {
-          "name": "Search Test",
-          "search_url": SEARCH_URL,
-        },
-      },
-    },
-    background,
-    useAddonManager: "temporary",
-  });
-  await extension.startup();
-
-  await clickBrowserAction(extension);
-  let url = await extension.awaitMessage("searchLoaded");
-  is(url, SEARCH_URL.replace("{searchTerms}", SEARCH_TERM), "Loaded page matches search");
-  await extension.unload();
-});

--- a/browser/components/extensions/test/mochitest/test_ext_all_apis.html
+++ b/browser/components/extensions/test/mochitest/test_ext_all_apis.html
@@ -11,17 +11,16 @@
 <body>
 <script>
 "use strict";
 /* exported expectedContentApisTargetSpecific, expectedBackgroundApisTargetSpecific */
 let expectedContentApisTargetSpecific = [
 ];
 
 let expectedBackgroundApisTargetSpecific = [
-  "search.get",
   "tabs.MutedInfoReason",
   "tabs.TAB_ID_NONE",
   "tabs.TabStatus",
   "tabs.UpdatePropertyName",
   "tabs.WindowType",
   "tabs.ZoomSettingsMode",
   "tabs.ZoomSettingsScope",
   "tabs.connect",