diff -r 000000000000 -r 6474c204b198 js/xpconnect/wrappers/WrapperFactory.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/xpconnect/wrappers/WrapperFactory.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,72 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* vim: set ts=8 sts=4 et sw=4 tw=99: */
+/* 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/. */
+
+#ifndef _xpc_WRAPPERFACTORY_H
+#define _xpc_WRAPPERFACTORY_H
+
+#include "jswrapper.h"
+
+namespace xpc {
+
+class WrapperFactory {
+  public:
+    enum { WAIVE_XRAY_WRAPPER_FLAG = js::Wrapper::LAST_USED_FLAG << 1,
+           IS_XRAY_WRAPPER_FLAG    = WAIVE_XRAY_WRAPPER_FLAG << 1 };
+
+    // Return true if any of any of the nested wrappers have the flag set.
+    static bool HasWrapperFlag(JSObject *wrapper, unsigned flag) {
+        unsigned flags = 0;
+        js::UncheckedUnwrap(wrapper, true, &flags);
+        return !!(flags & flag);
+    }
+
+    static bool IsXrayWrapper(JSObject *wrapper) {
+        return HasWrapperFlag(wrapper, IS_XRAY_WRAPPER_FLAG);
+    }
+
+    static bool HasWaiveXrayFlag(JSObject *wrapper) {
+        return HasWrapperFlag(wrapper, WAIVE_XRAY_WRAPPER_FLAG);
+    }
+
+    static bool IsSecurityWrapper(JSObject *obj) {
+        return !js::CheckedUnwrap(obj);
+    }
+
+    static bool IsCOW(JSObject *wrapper);
+
+    static JSObject *GetXrayWaiver(JS::HandleObject obj);
+    static JSObject *CreateXrayWaiver(JSContext *cx, JS::HandleObject obj);
+    static JSObject *WaiveXray(JSContext *cx, JSObject *obj);
+
+    static JSObject *DoubleWrap(JSContext *cx, JS::HandleObject obj, unsigned flags);
+
+    // Prepare a given object for wrapping in a new compartment.
+    static JSObject *PrepareForWrapping(JSContext *cx,
+                                        JS::HandleObject scope,
+                                        JS::HandleObject obj,
+                                        unsigned flags);
+
+    // Rewrap an object that is about to cross compartment boundaries.
+    static JSObject *Rewrap(JSContext *cx,
+                            JS::HandleObject existing,
+                            JS::HandleObject obj,
+                            JS::HandleObject wrappedProto,
+                            JS::HandleObject parent,
+                            unsigned flags);
+
+    // Wrap wrapped object into a waiver wrapper and then re-wrap it.
+    static bool WaiveXrayAndWrap(JSContext *cx, JS::MutableHandleValue vp);
+    static bool WaiveXrayAndWrap(JSContext *cx, JS::MutableHandleObject object);
+
+    // Returns true if the wrapper is in not shadowing mode for the id.
+    static bool XrayWrapperNotShadowing(JSObject *wrapper, jsid id);
+};
+
+extern js::Wrapper XrayWaiver;
+
+}
+
+#endif /* _xpc_WRAPPERFACTORY_H */