diff --git a/testing/specialpowers/content/SpecialPowersChild.jsm b/testing/specialpowers/content/SpecialPowersChild.jsm
index e94f7d719133..ec7fbef4e608 100644
--- a/testing/specialpowers/content/SpecialPowersChild.jsm
+++ b/testing/specialpowers/content/SpecialPowersChild.jsm
@@ -2141,10 +2141,6 @@ class SpecialPowersChild extends JSWindowActorChild {
       sendMessage(...args) {
         sp.sendAsyncMessage("SPExtensionMessage", { id, args });
       },
-
-      grantActiveTab(tabId) {
-        sp.sendAsyncMessage("SPExtensionGrantActiveTab", { id, tabId });
-      },
     };
 
     this.sendAsyncMessage("SPLoadExtension", { ext, id });
diff --git a/testing/specialpowers/content/SpecialPowersParent.jsm b/testing/specialpowers/content/SpecialPowersParent.jsm
index b5561a887579..cfc073f8fe98 100644
--- a/testing/specialpowers/content/SpecialPowersParent.jsm
+++ b/testing/specialpowers/content/SpecialPowersParent.jsm
@@ -1106,13 +1106,6 @@ class SpecialPowersParent extends JSWindowActorParent {
         return undefined;
       }
 
-      case "SPExtensionGrantActiveTab": {
-        let { id, tabId } = aMessage.data;
-        let { tabManager } = this._extensions.get(id);
-        tabManager.addActiveTabPermission(tabManager.get(tabId).nativeTab);
-        return undefined;
-      }
-
       case "SPUnloadExtension": {
         let id = aMessage.data.id;
         let extension = this._extensions.get(id);
diff --git a/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab.html b/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab.html
deleted file mode 100644
index 6c1675cb4751..000000000000
--- a/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab.html
+++ /dev/null
@@ -1,11 +0,0 @@
-<!DOCTYPE HTML>
-
-<html>
-<head>
-  <meta charset="utf-8">
-</head>
-<body>
-  <iframe id="emptyframe"></iframe>
-  <iframe id="regularframe" src="http://test1.example.com/"></iframe>
-</body>
-</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab2.html b/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab2.html
deleted file mode 100644
index 3b102b3d67cf..000000000000
--- a/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab2.html
+++ /dev/null
@@ -1,10 +0,0 @@
-<!DOCTYPE HTML>
-
-<html>
-<head>
-  <meta charset="utf-8">
-</head>
-<body>
-  <iframe srcdoc="<iframe src='http://test1.example.com/'&gt;</iframe&gt;"></iframe>
-</body>
-</html>
diff --git a/toolkit/components/extensions/test/mochitest/file_contentscript_iframe.html b/toolkit/components/extensions/test/mochitest/file_contentscript_iframe.html
deleted file mode 100644
index dda5169d69b3..000000000000
--- a/toolkit/components/extensions/test/mochitest/file_contentscript_iframe.html
+++ /dev/null
@@ -1,10 +0,0 @@
-<!DOCTYPE HTML>
-
-<html>
-<head>
-  <meta charset="utf-8">
-</head>
-<body>
-  <iframe id="frame" src="http://test2.example.com/"></iframe>
-</body>
-</html>
diff --git a/toolkit/components/extensions/test/mochitest/mochitest-common.ini b/toolkit/components/extensions/test/mochitest/mochitest-common.ini
index 3383a1100579..5b8192ab621f 100644
--- a/toolkit/components/extensions/test/mochitest/mochitest-common.ini
+++ b/toolkit/components/extensions/test/mochitest/mochitest-common.ini
@@ -7,9 +7,6 @@ support-files =
   file_WebRequest_page3.html
   file_contains_img.html
   file_contains_iframe.html
-  file_contentscript_activeTab.html
-  file_contentscript_activeTab2.html
-  file_contentscript_iframe.html
   file_image_bad.png
   file_image_good.png
   file_image_great.png
@@ -80,9 +77,6 @@ skip-if = os == 'android'
 skip-if = headless # Bug 1405872
 [test_ext_contentscript_about_blank.html]
 skip-if = os == 'android' # bug 1369440
-[test_ext_contentscript_activeTab.html]
-skip-if = os == 'android'
-fail-if = true # Broken by DocumentChannel
 [test_ext_contentscript_cache.html]
 skip-if = (os == 'linux' && debug) || (toolkit == 'android' && debug) # bug 1348241
 fail-if = xorigin # TypeError: can't access property "staticScripts", ext is undefined - Should not throw any errors
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_activeTab.html b/toolkit/components/extensions/test/mochitest/test_ext_contentscript_activeTab.html
deleted file mode 100644
index 306f093fe148..000000000000
--- a/toolkit/components/extensions/test/mochitest/test_ext_contentscript_activeTab.html
+++ /dev/null
@@ -1,371 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <title>Test for content script</title>
-  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
-  <script type="text/javascript" src="head.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
-</head>
-<body>
-
-<script type="text/javascript">
-"use strict";
-
-// Create a test extension with the provided function as the background
-// script.  The background script will have a few helpful functions
-// available.
-/* global awaitLoad, gatherFrameSources */
-function makeExtension(background) {
-  // Wait for a webNavigation.onCompleted event where the details for the
-  // loaded page match the attributes of `filter`.
-  function awaitLoad(filter) {
-    return new Promise(resolve => {
-      const listener = details => {
-        if (Object.keys(filter).every(key => details[key] === filter[key])) {
-          browser.webNavigation.onCompleted.removeListener(listener);
-          resolve();
-        }
-      };
-      browser.webNavigation.onCompleted.addListener(listener);
-    });
-  }
-
-  // Return a string with a (sorted) list of the source of all frames
-  // in the given tab into which this extension can inject scripts
-  // (ie all frames for which it has the activeTab permission).
-  // Source is the hostname for frames in http sources, or the full
-  // location href in other documents (eg about: pages)
-  async function gatherFrameSources(tabid) {
-    let result = await browser.tabs.executeScript(tabid, {
-      allFrames: true,
-      matchAboutBlank: true,
-      code: "window.location.hostname || window.location.href;",
-    });
-    return String(result.sort());
-  }
-
-  return ExtensionTestUtils.loadExtension({
-    manifest: {
-      permissions: ["activeTab", "webNavigation"],
-    },
-    background: `${awaitLoad}\n${gatherFrameSources}\n${ExtensionTestCommon.serializeScript(background)}`,
-  });
-}
-
-// Test that executeScript() fails without the activeTab permission
-// (or any specific origin permissions).
-add_task(async function test_no_activeTab() {
-  let extension = makeExtension(async function background() {
-    const URL = "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab.html";
-
-    let [tab] = await Promise.all([
-      browser.tabs.create({url: URL}),
-      awaitLoad({frameId: 0}),
-    ]);
-
-    try {
-      await gatherFrameSources(tab.id);
-      browser.test.fail("executeScript() should fail without activeTab permission");
-    } catch (err) {
-      browser.test.assertTrue(/^Missing host permission/.test(err.message),
-                              "executeScript() without activeTab permission failed");
-    }
-
-    await browser.tabs.remove(tab.id);
-
-    browser.test.notifyPass("no-active-tab");
-  });
-
-  await extension.startup();
-  await extension.awaitFinish("no-active-tab");
-  await extension.unload();
-});
-
-// Test that dynamically created iframes do not get the activeTab permission
-add_task(async function test_dynamic_frames() {
-  let extension = makeExtension(async function background() {
-    const BASE_HOST = "www.example.com";
-
-    let [tab] = await Promise.all([
-      browser.tabs.create({url: `http://${BASE_HOST}/`}),
-      awaitLoad({frameId: 0}),
-    ]);
-
-    function inject() {
-      let nframes = 4;
-      function frameLoaded() {
-        nframes--;
-        if (nframes == 0) {
-          browser.runtime.sendMessage("frames-loaded");
-        }
-      }
-
-      let frame = document.createElement("iframe");
-      frame.addEventListener("load", frameLoaded, {once: true});
-      document.body.appendChild(frame);
-
-      let div = document.createElement("div");
-      div.innerHTML = "<iframe src='http://test1.example.com/'></iframe>";
-      let framelist = div.getElementsByTagName("iframe");
-      browser.test.assertEq(1, framelist.length, "Found 1 frame inside div");
-      framelist[0].addEventListener("load", frameLoaded, {once: true});
-      document.body.appendChild(div);
-
-      let div2 = document.createElement("div");
-      div2.innerHTML = "<iframe srcdoc=\"<iframe src='http://test2.example.com/'&gt;</iframe&gt;\"></iframe>";
-      framelist = div2.getElementsByTagName("iframe");
-      browser.test.assertEq(1, framelist.length, "Found 1 frame inside div");
-      framelist[0].addEventListener("load", frameLoaded, {once: true});
-      document.body.appendChild(div2);
-
-      const URL = "http://www.example.com/tests/toolkit/components/extensions/test/mochitest/file_contentscript_iframe.html";
-
-      let xhr = new XMLHttpRequest();
-      xhr.open("GET", URL);
-      xhr.responseType = "document";
-      xhr.overrideMimeType("text/html");
-
-      xhr.addEventListener("load", () => {
-        if (xhr.readyState != 4) {
-          return;
-        }
-        if (xhr.status != 200) {
-          browser.runtime.sendMessage("error");
-        }
-
-        let frame = xhr.response.getElementById("frame");
-        browser.test.assertTrue(frame, "Found frame in response document");
-        frame.addEventListener("load", frameLoaded, {once: true});
-        document.body.appendChild(frame);
-      }, {once: true});
-      xhr.addEventListener("error", () => {
-        browser.runtime.sendMessage("error");
-      }, {once: true});
-      xhr.send();
-    }
-
-    browser.test.onMessage.addListener(async () => {
-      let loadedPromise = new Promise((resolve, reject) => {
-        let listener = msg => {
-          let unlisten = () => browser.runtime.onMessage.removeListener(listener);
-          if (msg == "frames-loaded") {
-            unlisten();
-            resolve();
-          } else if (msg == "error") {
-            unlisten();
-            reject();
-          }
-        };
-        browser.runtime.onMessage.addListener(listener);
-      });
-
-      await browser.tabs.executeScript(tab.id, {
-        code: `(${inject})();`,
-      });
-
-      await loadedPromise;
-
-      let result = await gatherFrameSources(tab.id);
-      browser.test.assertEq(String([BASE_HOST]), result,
-                            "Script is not injected into dynamically created frames");
-
-      await browser.tabs.remove(tab.id);
-
-      browser.test.notifyPass("dynamic-frames");
-    });
-
-    browser.test.sendMessage("ready", tab.id);
-  });
-
-  await extension.startup();
-
-  let tabId = await extension.awaitMessage("ready");
-  extension.grantActiveTab(tabId);
-
-  extension.sendMessage("go");
-  await extension.awaitFinish("dynamic-frames");
-
-  await extension.unload();
-});
-
-// Test that an iframe created from an <iframe srcdoc> gets the
-// activeTab permission.
-add_task(async function test_srcdoc() {
-  let extension = makeExtension(async function background() {
-    const URL = "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab2.html";
-    const OUTER_SOURCE = "about:srcdoc";
-    const PAGE_SOURCE = "mochi.test";
-    const FRAME_SOURCE = "test1.example.com";
-
-    let [tab] = await Promise.all([
-      browser.tabs.create({url: URL}),
-      awaitLoad({frameId: 0}),
-    ]);
-
-    browser.test.onMessage.addListener(async msg => {
-      if (msg == "go") {
-        let result = await gatherFrameSources(tab.id);
-        browser.test.assertEq(String([OUTER_SOURCE, PAGE_SOURCE, FRAME_SOURCE]),
-                              result,
-                              "Script is injected into frame created from <iframe srcdoc>");
-
-        await browser.tabs.remove(tab.id);
-
-        browser.test.notifyPass("srcdoc");
-      }
-    });
-
-    browser.test.sendMessage("ready", tab.id);
-  });
-
-  await extension.startup();
-
-  let tabId = await extension.awaitMessage("ready");
-  extension.grantActiveTab(tabId);
-
-  extension.sendMessage("go");
-  await extension.awaitFinish("srcdoc");
-
-  await extension.unload();
-});
-
-// Test that navigating frames by setting the src attribute from the
-// parent page revokes the activeTab permission.
-add_task(async function test_navigate_by_src() {
-  let extension = makeExtension(async function background() {
-    const URL = "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab.html";
-    const PAGE_SOURCE = "mochi.test";
-    const EMPTY_SOURCE = "about:blank";
-    const FRAME_SOURCE = "test1.example.com";
-
-    let [tab] = await Promise.all([
-      browser.tabs.create({url: URL}),
-      awaitLoad({frameId: 0}),
-    ]);
-
-    browser.test.onMessage.addListener(async msg => {
-      if (msg == "go") {
-        let result = await gatherFrameSources(tab.id);
-        browser.test.assertEq(String([EMPTY_SOURCE, PAGE_SOURCE, FRAME_SOURCE]),
-                              result,
-                              "In original page, script is injected into base page and original frames");
-
-        let loadedPromise = awaitLoad({tabId: tab.id});
-        await browser.tabs.executeScript(tab.id, {
-          code: "document.getElementById('emptyframe').src = 'http://test2.example.com/';",
-        });
-        await loadedPromise;
-
-        result = await gatherFrameSources(tab.id);
-        browser.test.assertEq(String([PAGE_SOURCE, FRAME_SOURCE]), result,
-                              "Script is not injected into initially empty frame after navigation");
-
-        loadedPromise = awaitLoad({tabId: tab.id});
-        await browser.tabs.executeScript(tab.id, {
-          code: "document.getElementById('regularframe').src = 'http://test2.example.com/';",
-        });
-        await loadedPromise;
-
-        result = await gatherFrameSources(tab.id);
-        browser.test.assertEq(String([PAGE_SOURCE]), result,
-                              "Script is not injected into regular frame after navigation");
-
-        await browser.tabs.remove(tab.id);
-        browser.test.notifyPass("test-scripts");
-      }
-    });
-
-    browser.test.sendMessage("ready", tab.id);
-  });
-
-  await extension.startup();
-
-  let tabId = await extension.awaitMessage("ready");
-  extension.grantActiveTab(tabId);
-
-  extension.sendMessage("go");
-  await extension.awaitFinish("test-scripts");
-
-  await extension.unload();
-});
-
-// Test that navigating frames by setting window.location from inside the
-// frame revokes the activeTab permission.
-add_task(async function test_navigate_by_window_location() {
-  let extension = makeExtension(async function background() {
-    const URL = "http://mochi.test:8888/tests/toolkit/components/extensions/test/mochitest/file_contentscript_activeTab.html";
-    const PAGE_SOURCE = "mochi.test";
-    const EMPTY_SOURCE = "about:blank";
-    const FRAME_SOURCE = "test1.example.com";
-
-    let [tab] = await Promise.all([
-      browser.tabs.create({url: URL}),
-      awaitLoad({frameId: 0}),
-    ]);
-
-    browser.test.onMessage.addListener(async msg => {
-      if (msg == "go") {
-        let result = await gatherFrameSources(tab.id);
-        browser.test.assertEq(String([EMPTY_SOURCE, PAGE_SOURCE, FRAME_SOURCE]),
-                              result,
-                              "Script initially injected into all frames");
-
-        let nframes = 0;
-        let frames = await browser.webNavigation.getAllFrames({tabId: tab.id});
-        for (let frame of frames) {
-          if (frame.parentFrameId == -1) {
-            continue;
-          }
-
-          let loadPromise = awaitLoad({
-            tabId: tab.id,
-            frameId: frame.frameId,
-          });
-
-          await browser.tabs.executeScript(tab.id, {
-            frameId: frame.frameId,
-            matchAboutBlank: true,
-            code: "window.location.href = 'https://test2.example.com/';",
-          });
-          await loadPromise;
-
-          try {
-            result = await browser.tabs.executeScript(tab.id, {
-              frameId: frame.frameId,
-              matchAboutBlank: true,
-              code: "window.location.hostname;",
-            });
-
-            browser.test.fail("executeScript should have failed on navigated frame");
-          } catch (err) {
-            browser.test.assertEq("Frame not found, or missing host permission", err.message);
-          }
-
-          nframes++;
-        }
-        browser.test.assertEq(2, nframes, "Found 2 frames");
-
-        await browser.tabs.remove(tab.id);
-        browser.test.notifyPass("scripted-navigation");
-      }
-    });
-
-    browser.test.sendMessage("ready", tab.id);
-  });
-
-  await extension.startup();
-
-  let tabId = await extension.awaitMessage("ready");
-  extension.grantActiveTab(tabId);
-
-  extension.sendMessage("go");
-  await extension.awaitFinish("scripted-navigation");
-
-  await extension.unload();
-});
-
-</script>
-
-</body>
-</html>
