diff -r 000000000000 -r 6474c204b198 dom/webidl/SettingsManager.webidl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/webidl/SettingsManager.webidl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,39 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/.
+ */
+
+[JSImplementation="@mozilla.org/settingsLock;1",
+ Pref="dom.mozSettings.enabled"]
+interface SettingsLock {
+  // Whether this lock is invalid
+  readonly attribute boolean closed;
+
+  // Contains a JSON object with name/value pairs to be set.
+  DOMRequest set(object settings);
+
+  // Result contains the value of the setting.
+  DOMRequest get(DOMString name);
+
+  DOMRequest clear();
+};
+
+dictionary SettingChange {
+  DOMString settingName;
+  DOMString settingValue;
+};
+
+callback SettingChangeCallback = void (SettingChange setting);
+
+[JSImplementation="@mozilla.org/settingsManager;1",
+ NavigatorProperty="mozSettings",
+ Pref="dom.mozSettings.enabled"]
+interface SettingsManager : EventTarget {
+  SettingsLock createLock();
+
+  void addObserver(DOMString name, SettingChangeCallback callback);
+  void removeObserver(DOMString name, SettingChangeCallback callback);
+
+  attribute EventHandler onsettingchange;
+};