diff -r 000000000000 -r 6474c204b198 widget/xpwidgets/nsClipboardPrivacyHandler.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/widget/xpwidgets/nsClipboardPrivacyHandler.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,41 @@
+/* -*- Mode: C++; 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/. */
+
+#ifndef nsClipboardPrivacyHandler_h__
+#define nsClipboardPrivacyHandler_h__
+
+#include "nsIObserver.h"
+#include "nsWeakReference.h"
+#include "nsCOMPtr.h"
+#include "mozilla/Attributes.h"
+
+class nsITransferable;
+
+// nsClipboardPrivacyHandler makes sure that clipboard data copied during
+// the private browsing mode does not leak after exiting this mode.
+// In order to ensure this, callers should store an object of this class
+// for their lifetime, and call PrepareDataForClipboard in their
+// nsIClipboard::SetData implementation before starting to use the
+// nsITransferable object in any way.
+
+class nsClipboardPrivacyHandler MOZ_FINAL : public nsIObserver,
+                                            public nsSupportsWeakReference
+{
+
+public:
+
+  // nsISupports
+  NS_DECL_ISUPPORTS
+
+  // nsIObserver  
+  NS_DECL_NSIOBSERVER
+
+  nsresult Init();
+  nsresult PrepareDataForClipboard(nsITransferable * aTransferable);
+};
+
+nsresult NS_NewClipboardPrivacyHandler(nsClipboardPrivacyHandler ** aHandler);
+
+#endif // nsClipboardPrivacyHandler_h__