Debugging code to print layer tree

ui/gfx/compositor/debug_utils.h

Index: ui/gfx/compositor/debug_utils.h
diff --git a/ui/gfx/compositor/debug_utils.h b/ui/gfx/compositor/debug_utils.h
new file mode 100644
index 0000000000000000000000000000000000000000..4987e4c5a6fb77fda242c43263e0488dae51a747
--- /dev/null
+++ b/ui/gfx/compositor/debug_utils.h
@@ -0,0 +1,22 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_GFX_COMPOSITOR_DEBUG_UTILS_H_
+#define UI_GFX_COMPOSITOR_DEBUG_UTILS_H_
+#pragma once
+
+#ifndef NDEBUG
+
+namespace ui {
+
+class Layer;
+
+// Log the layer hierarchy.
+void PrintLayerHierarchy(const Layer* layer);
+
+} // namespace ui
+
+#endif // NDEBUG
+
+#endif  // UI_GFX_COMPOSITOR_DEBUG_UTILS_H_