--- a/dom/ipc/ContentChild.cpp
+++ b/dom/ipc/ContentChild.cpp
@@ -152,20 +152,18 @@
 
 #include "nsIScriptSecurityManager.h"
 #include "nsHostObjectProtocolHandler.h"
 
 #ifdef MOZ_WEBRTC
 #include "signaling/src/peerconnection/WebrtcGlobalChild.h"
 #endif
 
-#ifdef MOZ_PERMISSIONS
 #include "nsPermission.h"
 #include "nsPermissionManager.h"
-#endif
 
 #include "PermissionMessageUtils.h"
 
 #if defined(MOZ_WIDGET_ANDROID)
 #include "APKOpen.h"
 #endif
 
 #ifdef XP_WIN
@@ -2541,17 +2539,16 @@ ContentChild::RecvUpdateRequestedLocales
 {
   LocaleService::GetInstance()->AssignRequestedLocales(aRequestedLocales);
   return IPC_OK();
 }
 
 mozilla::ipc::IPCResult
 ContentChild::RecvAddPermission(const IPC::Permission& permission)
 {
-#if MOZ_PERMISSIONS
   nsCOMPtr<nsIPermissionManager> permissionManagerIface =
     services::GetPermissionManager();
   nsPermissionManager* permissionManager =
     static_cast<nsPermissionManager*>(permissionManagerIface.get());
   MOZ_ASSERT(permissionManager,
          "We have no permissionManager in the Content process !");
 
   // note we do not need to force mUserContextId to the default here because
@@ -2574,17 +2571,16 @@ ContentChild::RecvAddPermission(const IP
                                  nsCString(permission.type),
                                  permission.capability,
                                  0,
                                  permission.expireType,
                                  permission.expireTime,
                                  modificationTime,
                                  nsPermissionManager::eNotify,
                                  nsPermissionManager::eNoDBOperation);
-#endif
 
   return IPC_OK();
 }
 
 mozilla::ipc::IPCResult
 ContentChild::RecvFlushMemory(const nsString& reason)
 {
   nsCOMPtr<nsIObserverService> os =

--- a/dom/ipc/ContentParent.cpp
+++ b/dom/ipc/ContentParent.cpp
@@ -207,19 +207,17 @@
 #if defined(XP_LINUX)
 #include "mozilla/Hal.h"
 #endif
 
 #ifdef ANDROID
 # include "gfxAndroidPlatform.h"
 #endif
 
-#ifdef MOZ_PERMISSIONS
 # include "nsPermissionManager.h"
-#endif
 
 #ifdef MOZ_WIDGET_ANDROID
 # include "AndroidBridge.h"
 #endif
 
 #ifdef MOZ_WIDGET_GTK
 #include <gdk/gdk.h>
 #endif
@@ -5179,33 +5177,30 @@ ContentParent::AboutToLoadHttpFtpWyciwyg
   }
 
   return NS_OK;
 }
 
 nsresult
 ContentParent::TransmitPermissionsForPrincipal(nsIPrincipal* aPrincipal)
 {
-#ifdef MOZ_PERMISSIONS
   // Create the key, and send it down to the content process.
   nsTArray<nsCString> keys =
     nsPermissionManager::GetAllKeysForPrincipal(aPrincipal);
   MOZ_ASSERT(keys.Length() >= 1);
   for (auto& key : keys) {
     EnsurePermissionsByKey(key);
   }
-#endif
 
   return NS_OK;
 }
 
 void
 ContentParent::EnsurePermissionsByKey(const nsCString& aKey)
 {
-#ifdef MOZ_PERMISSIONS
   // NOTE: Make sure to initialize the permission manager before updating the
   // mActivePermissionKeys list. If the permission manager is being initialized
   // by this call to GetPermissionManager, and we've added the key to
   // mActivePermissionKeys, then the permission manager will send down a
   // SendAddPermission before receiving the SendSetPermissionsWithKey message.
   nsCOMPtr<nsIPermissionManager> permManager =
     services::GetPermissionManager();
 
@@ -5216,17 +5211,16 @@ ContentParent::EnsurePermissionsByKey(co
 
   nsTArray<IPC::Permission> perms;
   nsresult rv = permManager->GetPermissionsWithKey(aKey, perms);
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return;
   }
 
   Unused << SendSetPermissionsWithKey(aKey, perms);
-#endif
 }
 
 bool
 ContentParent::NeedsPermissionsUpdate(const nsACString& aPermissionKey) const
 {
   return mActivePermissionKeys.Contains(aPermissionKey);
 }
 

--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -509,26 +509,16 @@ def legacy_extensions(value):
 set_config('MOZ_ALLOW_LEGACY_EXTENSIONS', legacy_extensions)
 set_define('MOZ_ALLOW_LEGACY_EXTENSIONS', legacy_extensions)
 
 @depends('MOZ_PLACES', 'MOZ_ANDROID_HISTORY')
 def check_places_and_android_history(places, android_history):
     if places and android_history:
         die('Cannot use MOZ_ANDROID_HISTORY alongside MOZ_PLACES.')
 
-# Permissions system
-# ==============================================================
-option(name='--disable-permissions',
-       help='Disable permissions (popup and cookie blocking)')
-
-moz_permissions = depends_if('--disable-permissions')(lambda _: True)
-
-set_config('MOZ_PERMISSIONS', moz_permissions)
-set_define('MOZ_PERMISSIONS', moz_permissions)
-
 # gpsd support
 # ==============================================================
 option('--enable-gpsd', env='MOZ_GPSD',
        help='Enable gpsd support')
 
 @depends('--enable-gpsd')
 def gpsd(value):
     return bool(value)

--- a/toolkit/toolkit.mozbuild
+++ b/toolkit/toolkit.mozbuild
@@ -78,21 +78,20 @@ DIRS += [
     '/storage',
 ]
 
 if CONFIG['COMPILE_ENVIRONMENT']:
     DIRS += [
         '/media/libyuv',
     ]
 
-if CONFIG['MOZ_PERMISSIONS']:
-    DIRS += [
-        '/extensions/cookie',
-        '/extensions/permissions',
-    ]
+DIRS += [
+    '/extensions/cookie',
+    '/extensions/permissions',
+]
 
 DIRS += [
     '/rdf',
 ]
 
 if CONFIG['MOZ_WEBRTC'] and CONFIG['COMPILE_ENVIRONMENT']:
     DIRS += [
         '/media/webrtc',