diff -r 000000000000 -r 6474c204b198 dom/base/ObjectWrapper.jsm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/base/ObjectWrapper.jsm	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,52 @@
+/* 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"
+
+const Cu = Components.utils;
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+this.EXPORTED_SYMBOLS = ["ObjectWrapper"];
+
+// Makes sure that we expose correctly chrome JS objects to content.
+
+const TypedArrayThings = [
+  "Int8Array",
+  "Uint8Array",
+  "Uint8ClampedArray",
+  "Int16Array",
+  "Uint16Array",
+  "Int32Array",
+  "Uint32Array",
+  "Float32Array",
+  "Float64Array",
+];
+
+this.ObjectWrapper = {
+  getObjectKind: function objWrapper_getObjectKind(aObject) {
+    if (aObject === null || aObject === undefined) {
+      return "primitive";
+    } else if (Array.isArray(aObject)) {
+      return "array";
+    } else if (aObject instanceof Ci.nsIDOMFile) {
+      return "file";
+    } else if (aObject instanceof Ci.nsIDOMBlob) {
+      return "blob";
+    } else if (aObject instanceof Date) {
+      return "date";
+    } else if (TypedArrayThings.indexOf(aObject.constructor.name) !== -1) {
+      return aObject.constructor.name;
+    } else if (typeof aObject == "object") {
+      return "object";
+    } else {
+      return "primitive";
+    }
+  },
+
+  wrap: function objWrapper_wrap(aObject, aCtxt) {
+    dump("-*- ObjectWrapper is deprecated. Use Components.utils.cloneInto() instead.\n");
+    return Cu.cloneInto(aObject, aCtxt, { cloneFunctions: true });
+  }
+}