diff --git a/dom/base/test/chrome/test_bug1339722.html b/dom/base/test/chrome/test_bug1339722.html
index b0d3f60aa39e..288cbbfcdce5 100644
--- a/dom/base/test/chrome/test_bug1339722.html
+++ b/dom/base/test/chrome/test_bug1339722.html
@@ -1,67 +1,91 @@
-<!DOCTYPE HTML>
+<!DOCTYPE html>
 <html>
-<!--
+  <!--
 https://bugzilla.mozilla.org/show_bug.cgi?id=1339722
 -->
-<head>
-  <meta charset="utf-8">
-  <title>Test for Bug 1339722</title>
-  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
-  <link rel="stylesheet" type="text/css" href="chrome://global/skin"/>
-  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
-  <script type="application/javascript">
+  <head>
+    <meta charset="utf-8" />
+    <title>Test for Bug 1339722</title>
+    <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+    <link rel="stylesheet" type="text/css" href="chrome://global/skin" />
+    <link
+      rel="stylesheet"
+      type="text/css"
+      href="chrome://mochikit/content/tests/SimpleTest/test.css"
+    />
+    <script type="application/javascript">
+      /**
+       * Test for Bug 1339722
+       * 1. Wait for "http-on-modify-request" or document-on-modify-request for the
+       *    iframe load.
+       * 2. In the observer, access it's window proxy to trigger DOMWindowCreated.
+       * 3. In the event handler, delete the iframe so that the frameloader would be
+       *    destroyed in the middle of ReallyStartLoading.
+       * 4. Verify that it doesn't crash.
+       **/
 
-  /**
-   * Test for Bug 1339722
-   * 1. Wait for "http-on-modify-request" for the iframe load.
-   * 2. In the observer, access it's window proxy to trigger DOMWindowCreated.
-   * 3. In the event handler, delete the iframe so that the frameloader would be
-   *    destoryed in the middle of ReallyStartLoading.
-   * 4. Verify that it doesn't crash.
-  **/
+      const { Services } = ChromeUtils.import(
+        "resource://gre/modules/Services.jsm"
+      );
+      // This topic used to be http-on-useragent-request, but that got removed in
+      // bug 1513574. on-modify-request is called around the same time, and should
+      // behave similarly.
+      const TOPIC = SpecialPowers.getBoolPref("browser.tabs.documentchannel")
+        ? "document-on-modify-request"
+        : "http-on-modify-request";
+      let win;
+      const observe = (subject, topic, data) => {
+        info("Got " + topic);
+        Services.obs.removeObserver(observe, TOPIC);
 
-  const {Services} = ChromeUtils.import("resource://gre/modules/Services.jsm");
+        // Query window proxy so it triggers DOMWindowCreated.
+        let channel;
+        try {
+          // We need to QI nsIHttpChannel in order to load the interface's
+          // methods / attributes for later code that could assume we are dealing
+          // with a nsIHttpChannel.
+          channel = subject.QueryInterface(Ci.nsIHttpChannel);
+        } catch (e) {
+          channel = subject.QueryInterface(Ci.nsIIdentChannel);
+        }
+        win = channel.notificationCallbacks.getInterface(Ci.mozIDOMWindowProxy);
+      };
 
-  // This topic used to be http-on-useragent-request, but that got removed in
-  // bug 1513574. on-modify-request is called around the same time, and should
-  // behave similarly.
-  const TOPIC = "http-on-modify-request";
-  let win;
-  Services.obs.addObserver({
-    observe(subject, topic, data) {
-      info("Got " + topic);
-      Services.obs.removeObserver(this, TOPIC);
+      Services.obs.addObserver(observe, TOPIC);
 
-      // Query window proxy so it triggers DOMWindowCreated.
-      let channel = subject.QueryInterface(Ci.nsIHttpChannel);
-      win = channel.notificationCallbacks.getInterface(Ci.mozIDOMWindowProxy);
-    },
-  }, TOPIC);
+      let docShell = SpecialPowers.wrap(window).docShell;
+      docShell.chromeEventHandler.addEventListener(
+        "DOMWindowCreated",
+        function handler(e) {
+          info("Got DOMWindowCreated");
+          let iframe = document.getElementById("testFrame");
+          is(e.target, iframe.contentDocument, "verify event target");
 
-  let docShell = SpecialPowers.wrap(window).docShell;
-  docShell.chromeEventHandler.addEventListener("DOMWindowCreated", function handler(e) {
-    let iframe = document.getElementById("testFrame");
-    is(e.target, iframe.contentDocument, "verify event target");
+          // Remove the iframe to cause frameloader destroy.
+          iframe.remove();
+          setTimeout(($) => {
+            ok(!document.getElementById("testFrame"), "verify iframe removed");
+            SimpleTest.finish();
+          }, 0);
+        },
+        { once: true }
+      );
 
-    // Remove the iframe to cause frameloader destroy.
-    iframe.remove();
-    setTimeout($ => {
-      ok(!document.getElementById("testFrame"), "verify iframe removed");
-      SimpleTest.finish();
-    }, 0);
-  }, {once: true});
-
-  SimpleTest.waitForExplicitFinish();
-  </script>
-</head>
-<body>
-<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1339722">Mozilla Bug 1339722</a>
-<p id="display"></p>
-<div id="content" style="display: none"></div>
-<pre id="test">
+      SimpleTest.waitForExplicitFinish();
+    </script>
+  </head>
+  <body>
+    <a
+      target="_blank"
+      href="https://bugzilla.mozilla.org/show_bug.cgi?id=1339722"
+      >Mozilla Bug 1339722</a
+    >
+    <p id="display"></p>
+    <div id="content" style="display: none;"></div>
+    <pre id="test">
   <div id="frameContainer">
     <iframe id="testFrame" src="http://www.example.com"></iframe>
   </div>
 </pre>
-</body>
+  </body>
 </html>
