diff -r 000000000000 -r 6474c204b198 gfx/layers/ipc/PGrallocBuffer.ipdl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/layers/ipc/PGrallocBuffer.ipdl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* 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/. */
+
+include protocol PCompositor;
+include protocol PImageBridge;
+include protocol PLayerTransaction;
+
+namespace mozilla {
+namespace layers {
+
+/**
+ * This is a trivial protocol that's used to track gralloc buffers
+ * across thread contexts.  A live PGrallocBuffer actor always
+ * corresponds 1:1 to a pre-shared gralloc buffer (sharing is done by
+ * the PGrallocBuffer constructor).
+ */
+async protocol PGrallocBuffer {
+  manager PImageBridge or PLayerTransaction;
+
+  /** Gralloc buffers can be "owned" by either parent or child. */
+both:
+  async __delete__();
+};
+
+} // namespace layers
+} // namespace mozilla