--- a/browser/app/moz.build
+++ b/browser/app/moz.build
@@ -12,17 +12,16 @@ JS_PREFERENCE_PP_FILES += [
     'profile/firefox.js',
 ]
 
 SOURCES += [
     'nsBrowserApp.cpp',
 ]
 
 FINAL_TARGET_FILES += ['blocklist.xml']
-FINAL_TARGET_FILES.defaults.profile += ['profile/prefs.js']
 FINAL_TARGET_FILES.defaults += ['permissions']
 
 DEFINES['APP_VERSION'] = CONFIG['MOZ_APP_VERSION']
 
 LOCAL_INCLUDES += [
     '!/build',
     '/toolkit/xre',
     '/xpcom/base',

deleted file mode 100644
--- a/browser/app/profile/prefs.js
+++ /dev/null
@@ -1,13 +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/. */
-
-# Mozilla User Preferences
-
-/* Do not edit this file.
- *
- * If you make changes to this file while the browser is running,
- * the changes will be overwritten when the browser exits.
- *
- * To make a manual change to preferences, you can visit the URL about:config
- */

--- a/browser/base/content/test/static/browser_all_files_referenced.js
+++ b/browser/base/content/test/static/browser_all_files_referenced.js
@@ -283,19 +283,16 @@ const ignorableWhitelist = new Set([
   "resource://app/blocklist.xml",
 
   // dom/media/gmp/GMPParent.cpp
   "resource://gre/gmp-clearkey/0.1/manifest.json",
 
   // Bug 1351675 - should this file be packaged?
   "resource://app/defaults/pinning/pins.json",
 
-  // Bug 1351682 - should be removed?
-  "resource://app/defaults/profile/prefs.js",
-
   // Bug 1351669 - obsolete test file
   "resource://gre/res/test.properties",
 ]);
 for (let entry of ignorableWhitelist) {
   whitelist.add(entry);
 }
 
 if (!isDevtools) {

--- a/browser/base/content/test/static/browser_parsable_script.js
+++ b/browser/base/content/test/static/browser_parsable_script.js
@@ -1,17 +1,16 @@
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 
 /* This list allows pre-existing or 'unfixable' JS issues to remain, while we
  * detect newly occurring issues in shipping JS. It is a list of regexes
  * matching files which have errors:
  */
 const kWhitelist = new Set([
-  /defaults\/profile\/prefs.js$/,
   /browser\/content\/browser\/places\/controller.js$/,
 ]);
 
 // Normally we would use reflect.jsm to get Reflect.parse. However, if
 // we do that, then all the AST data is allocated in reflect.jsm's
 // zone. That exposes a bug in our GC. The GC collects reflect.jsm's
 // zone but not the zone in which our test code lives (since no new
 // data is being allocated in it). The cross-compartment wrappers in