--- a/browser/components/newtab/aboutNewTabService.js
+++ b/browser/components/newtab/aboutNewTabService.js
@@ -103,16 +103,17 @@ AboutNewTabService.prototype = {
     Ci.nsIObserver
   ]),
 
   observe(subject, topic, data) {
     switch (topic) {
       case "nsPref:changed":
         if (data === PREF_SEPARATE_PRIVILEGED_CONTENT_PROCESS) {
           this._privilegedContentProcess = Services.prefs.getBoolPref(PREF_SEPARATE_PRIVILEGED_CONTENT_PROCESS);
+          this.notifyChange();
         } else if (data === PREF_ACTIVITY_STREAM_PRERENDER_ENABLED) {
           this._activityStreamPrerender = Services.prefs.getBoolPref(PREF_ACTIVITY_STREAM_PRERENDER_ENABLED);
           this.notifyChange();
         } else if (!IS_RELEASE_OR_BETA && data === PREF_ACTIVITY_STREAM_DEBUG) {
           this._activityStreamDebug = Services.prefs.getBoolPref(PREF_ACTIVITY_STREAM_DEBUG, false);
           this.updatePrerenderedPath();
           this.notifyChange();
         }

--- a/browser/components/newtab/test/browser/browser_packaged_as_locales.js
+++ b/browser/components/newtab/test/browser/browser_packaged_as_locales.js
@@ -1,15 +1,17 @@
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 XPCOMUtils.defineLazyServiceGetter(this, "aboutNewTabService",
                                    "@mozilla.org/browser/aboutnewtab-service;1",
                                    "nsIAboutNewTabService");
 
 // Tests are by default run with non-debug en-US configuration
-const DEFAULT_URL = "resource://activity-stream/prerendered/en-US/activity-stream-prerendered.html";
+const DEFAULT_URL = SpecialPowers.getBoolPref("browser.tabs.remote.separatePrivilegedContentProcess")
+  ? "resource://activity-stream/prerendered/en-US/activity-stream-prerendered-noscripts.html"
+  : "resource://activity-stream/prerendered/en-US/activity-stream-prerendered.html";
 
 /**
  * Temporarily change the app locale to get the localized activity stream url
  */
 async function getUrlForLocale(locale) {
   const origAvailable = Services.locale.getAvailableLocales();
   const origRequested = Services.locale.getRequestedLocales();
   try {

--- a/browser/components/newtab/test/xpcshell/test_AboutNewTabService.js
+++ b/browser/components/newtab/test/xpcshell/test_AboutNewTabService.js
@@ -9,33 +9,65 @@ ChromeUtils.import("resource://gre/modul
 ChromeUtils.import("resource://gre/modules/Preferences.jsm");
 ChromeUtils.import("resource://gre/modules/AppConstants.jsm");
 XPCOMUtils.defineLazyServiceGetter(this, "aboutNewTabService",
                                    "@mozilla.org/browser/aboutnewtab-service;1",
                                    "nsIAboutNewTabService");
 
 const IS_RELEASE_OR_BETA = AppConstants.RELEASE_OR_BETA;
 
-const ACTIVITY_STREAM_PRERENDER_URL = "resource://activity-stream/prerendered/en-US/activity-stream-prerendered.html";
-const ACTIVITY_STREAM_PRERENDER_DEBUG_URL = "resource://activity-stream/prerendered/static/activity-stream-prerendered-debug.html";
-const ACTIVITY_STREAM_URL = "resource://activity-stream/prerendered/en-US/activity-stream.html";
-const ACTIVITY_STREAM_DEBUG_URL = "resource://activity-stream/prerendered/static/activity-stream-debug.html";
-
 const DOWNLOADS_URL = "chrome://browser/content/downloads/contentAreaDownloadsView.xul";
+const SEPARATE_PRIVILEGED_CONTENT_PROCESS_PREF = "browser.tabs.remote.separatePrivilegedContentProcess";
 const ACTIVITY_STREAM_PRERENDER_PREF = "browser.newtabpage.activity-stream.prerender";
 const ACTIVITY_STREAM_DEBUG_PREF = "browser.newtabpage.activity-stream.debug";
 
 function cleanup() {
+  Services.prefs.clearUserPref(SEPARATE_PRIVILEGED_CONTENT_PROCESS_PREF);
   Services.prefs.clearUserPref(ACTIVITY_STREAM_PRERENDER_PREF);
   Services.prefs.clearUserPref(ACTIVITY_STREAM_DEBUG_PREF);
   aboutNewTabService.resetNewTabURL();
 }
 
 registerCleanupFunction(cleanup);
 
+let ACTIVITY_STREAM_PRERENDER_URL;
+let ACTIVITY_STREAM_PRERENDER_DEBUG_URL;
+let ACTIVITY_STREAM_URL;
+let ACTIVITY_STREAM_DEBUG_URL;
+
+function setExpectedUrlsWithScripts() {
+  ACTIVITY_STREAM_PRERENDER_URL = "resource://activity-stream/prerendered/en-US/activity-stream-prerendered.html";
+  ACTIVITY_STREAM_PRERENDER_DEBUG_URL = "resource://activity-stream/prerendered/static/activity-stream-prerendered-debug.html";
+  ACTIVITY_STREAM_URL = "resource://activity-stream/prerendered/en-US/activity-stream.html";
+  ACTIVITY_STREAM_DEBUG_URL = "resource://activity-stream/prerendered/static/activity-stream-debug.html";
+}
+
+function setExpectedUrlsWithoutScripts() {
+  ACTIVITY_STREAM_PRERENDER_URL = "resource://activity-stream/prerendered/en-US/activity-stream-prerendered-noscripts.html";
+  ACTIVITY_STREAM_PRERENDER_DEBUG_URL = "resource://activity-stream/prerendered/static/activity-stream-prerendered-debug-noscripts.html";
+  ACTIVITY_STREAM_URL = "resource://activity-stream/prerendered/en-US/activity-stream-noscripts.html";
+  ACTIVITY_STREAM_DEBUG_URL = "resource://activity-stream/prerendered/static/activity-stream-debug-noscripts.html";
+}
+
+// Default expected URLs to files with scripts in them.
+setExpectedUrlsWithScripts();
+
+function addTestsWithPrivilegedContentProcessPref(test) {
+  add_task(async() => {
+    await setPrivilegedContentProcessPref(true);
+    setExpectedUrlsWithoutScripts();
+    await test();
+  });
+  add_task(async() => {
+    await setPrivilegedContentProcessPref(false);
+    setExpectedUrlsWithScripts();
+    await test();
+  });
+}
+
 function nextChangeNotificationPromise(aNewURL, testMessage) {
   return new Promise(resolve => {
     Services.obs.addObserver(function observer(aSubject, aTopic, aData) { // jshint unused:false
       Services.obs.removeObserver(observer, aTopic);
       Assert.equal(aData, aNewURL, testMessage);
       resolve();
     }, "newtab-url-changed");
   });
@@ -58,16 +90,26 @@ function setupASPrerendered() {
     return Promise.resolve();
   }
 
   let notificationPromise = nextChangeNotificationPromise("about:newtab");
   Services.prefs.setBoolPref(ACTIVITY_STREAM_PRERENDER_PREF, true);
   return notificationPromise;
 }
 
+function setPrivilegedContentProcessPref(usePrivilegedContentProcess) {
+  if (usePrivilegedContentProcess === Services.prefs.getBoolPref(SEPARATE_PRIVILEGED_CONTENT_PROCESS_PREF)) {
+    return Promise.resolve();
+  }
+
+  let notificationPromise = nextChangeNotificationPromise("about:newtab");
+  Services.prefs.setBoolPref(SEPARATE_PRIVILEGED_CONTENT_PROCESS_PREF, usePrivilegedContentProcess);
+  return notificationPromise;
+}
+
 add_task(async function test_as_and_prerender_initialized() {
   Assert.ok(aboutNewTabService.activityStreamEnabled,
     ".activityStreamEnabled should be set to the correct initial value");
   Assert.equal(aboutNewTabService.activityStreamPrerender, Services.prefs.getBoolPref(ACTIVITY_STREAM_PRERENDER_PREF),
     ".activityStreamPrerender should be set to the correct initial value");
   // This pref isn't defined on release or beta, so we fall back to false
   Assert.equal(aboutNewTabService.activityStreamDebug, Services.prefs.getBoolPref(ACTIVITY_STREAM_DEBUG_PREF, false),
     ".activityStreamDebug should be set to the correct initial value");
@@ -100,20 +142,21 @@ add_task(async function test_override_ac
   aboutNewTabService.newTabURL = DOWNLOADS_URL;
   await notificationPromise;
   Assert.ok(aboutNewTabService.overridden, "Newtab URL should be overridden");
   Assert.equal(aboutNewTabService.newTabURL, DOWNLOADS_URL, "Newtab URL should be the custom URL");
 
   cleanup();
 });
 
-add_task(async function test_override_activity_stream_enabled() {
+addTestsWithPrivilegedContentProcessPref(async function test_override_activity_stream_enabled() {
   let notificationPromise = await setupASPrerendered();
 
-  Assert.equal(aboutNewTabService.defaultURL, ACTIVITY_STREAM_PRERENDER_URL, "Newtab URL should be the default activity stream prerendered URL");
+  Assert.equal(aboutNewTabService.defaultURL, ACTIVITY_STREAM_PRERENDER_URL,
+    "Newtab URL should be the default activity stream prerendered URL");
   Assert.ok(!aboutNewTabService.overridden, "Newtab URL should not be overridden");
   Assert.ok(aboutNewTabService.activityStreamEnabled, "Activity Stream should be enabled");
   Assert.ok(aboutNewTabService.activityStreamPrerender, "Activity Stream should be prerendered");
 
   // change to a chrome URL while activity stream is enabled
   notificationPromise = nextChangeNotificationPromise(DOWNLOADS_URL);
   aboutNewTabService.newTabURL = DOWNLOADS_URL;
   await notificationPromise;
@@ -122,18 +165,19 @@ add_task(async function test_override_ac
   Assert.equal(aboutNewTabService.defaultURL, ACTIVITY_STREAM_PRERENDER_URL,
                "Newtab URL defaultURL still set to the default activity stream prerendered URL");
   Assert.ok(aboutNewTabService.overridden, "Newtab URL should be overridden");
   Assert.ok(!aboutNewTabService.activityStreamEnabled, "Activity Stream should not be enabled");
 
   cleanup();
 });
 
-add_task(async function test_default_url() {
+addTestsWithPrivilegedContentProcessPref(async function test_default_url() {
   await setupASPrerendered();
+
   Assert.equal(aboutNewTabService.defaultURL, ACTIVITY_STREAM_PRERENDER_URL,
     "Newtab defaultURL initially set to prerendered AS url");
 
   // Only debug variants aren't available on release/beta
   if (!IS_RELEASE_OR_BETA) {
     await setBoolPrefAndWaitForChange(ACTIVITY_STREAM_DEBUG_PREF, true,
       "A notification occurs after changing the debug pref to true");
     Assert.equal(aboutNewTabService.activityStreamDebug, true,
@@ -156,17 +200,17 @@ add_task(async function test_default_url
   }
 
   Assert.equal(aboutNewTabService.defaultURL, ACTIVITY_STREAM_URL,
     "Newtab defaultURL set to un-prerendered AS if prerender is false and debug is false");
 
   cleanup();
 });
 
-add_task(async function test_welcome_url() {
+addTestsWithPrivilegedContentProcessPref(async function test_welcome_url() {
   await setupASPrerendered();
 
   Assert.equal(aboutNewTabService.activityStreamPrerender, true,
     "Prerendering is enabled by default.");
   Assert.equal(aboutNewTabService.welcomeURL, ACTIVITY_STREAM_URL,
     "Newtab welcomeURL set to un-prerendered AS when prerendering enabled and debug disabled.");
   await setBoolPrefAndWaitForChange(ACTIVITY_STREAM_PRERENDER_PREF, false,
     "A notification occurs after changing the prerender pref to false.");
@@ -189,21 +233,21 @@ add_task(async function test_welcome_url
 });
 
 add_task(function test_locale() {
   Assert.equal(aboutNewTabService.activityStreamLocale, "en-US",
     "The locale for testing should be en-US");
 });
 
 /**
- * Tests reponse to updates to prefs
+ * Tests response to updates to prefs
  */
-add_task(async function test_updates() {
-   // Simulates a "cold-boot" situation, with some pref already set before testing a series
-   // of changes.
+addTestsWithPrivilegedContentProcessPref(async function test_updates() {
+  // Simulates a "cold-boot" situation, with some pref already set before testing a series
+  // of changes.
   await setupASPrerendered();
 
   aboutNewTabService.resetNewTabURL(); // need to set manually because pref notifs are off
   let notificationPromise;
 
   // test update fires on override and reset
   let testURL = "https://example.com/";
   notificationPromise = nextChangeNotificationPromise(