Bug 936623 - Deprecate Widget

lib/sdk/widget.js

@@ -1,13 +1,12 @@
 /* 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/. */
-
 "use strict";
 
 // The widget module currently supports only Firefox.
 // See: https://bugzilla.mozilla.org/show_bug.cgi?id=560716
 module.metadata = {
-  "stability": "stable",
+  "stability": "deprecated",
   "engines": {
     "Firefox": "*"
   }
@@ -55,6 +54,11 @@ const unload = require("./system/unload");
 const { getNodeView } = require("./view/core");
 const prefs = require('./preferences/service');
 
+require("./util/deprecate").deprecateUsage(
+  "The widget module is deprecated.  " +
+  "Please consider using the sdk/ui module instead."
+);
+
 // Data types definition
 const valid = {
   number: { is: ["null", "undefined", "number"] },