diff -r 000000000000 -r 6474c204b198 dom/bindings/CallbackInterface.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/bindings/CallbackInterface.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* 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/. */
+
+/**
+ * A common base class for representing WebIDL callback interface types in C++.
+ *
+ * This class implements common functionality like lifetime management,
+ * initialization with the callback object, and setup of the call environment.
+ * Subclasses corresponding to particular callback interface types should
+ * provide methods that actually do the various necessary calls.
+ */
+
+#ifndef mozilla_dom_CallbackInterface_h
+#define mozilla_dom_CallbackInterface_h
+
+#include "mozilla/dom/CallbackObject.h"
+
+namespace mozilla {
+namespace dom {
+
+class CallbackInterface : public CallbackObject
+{
+public:
+  explicit CallbackInterface(JS::Handle<JSObject*> aCallback,
+                             nsIGlobalObject *aIncumbentGlobal)
+    : CallbackObject(aCallback, aIncumbentGlobal)
+  {
+  }
+
+protected:
+  bool GetCallableProperty(JSContext* cx, const char* aPropName,
+                           JS::MutableHandle<JS::Value> aCallable);
+
+};
+
+} // namespace dom
+} // namespace mozilla
+
+#endif // mozilla_dom_CallbackFunction_h