diff -r 000000000000 -r 6474c204b198 gfx/tests/gtest/TestLayers.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/tests/gtest/TestLayers.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,36 @@
+/* vim:set ts=2 sw=2 sts=2 et: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+#ifndef GFX_TEST_LAYERS_H
+#define GFX_TEST_LAYERS_H
+
+#include "Layers.h"
+#include "nsTArray.h"
+
+/* Create layer tree from a simple layer tree description syntax.
+ * Each index is either the first letter of the layer type or
+ * a '(',')' to indicate the start/end of the child layers.
+ * The aim of this function is to remove hard to read
+ * layer tree creation code.
+ *
+ * Example "c(c(c(tt)t))" would yield:
+ *          c
+ *          |
+ *          c
+ *         / \
+ *        c   t
+ *       / \
+ *      t   t
+ */
+already_AddRefed<mozilla::layers::Layer> CreateLayerTree(
+    const char* aLayerTreeDescription,
+    nsIntRegion* aVisibleRegions,
+    const gfx3DMatrix* aTransforms,
+    nsRefPtr<mozilla::layers::LayerManager>& aLayerManager,
+    nsTArray<nsRefPtr<mozilla::layers::Layer> >& aLayersOut);
+
+
+#endif
+