Initial checkin of the new Mozart compositor.

mojo/services/gfx/composition/interfaces/scene_token.mojom

+// Copyright 2015 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.
+
+[DartPackage="mojo_services"]
+module mojo.gfx.composition;
+
+// A scene token is an opaque transferable reference to a scene.
+//
+// Each scene is associated with a unique scene token at creation time.
+// This token can be used to create references from one scene to another
+// or to create a renderer for a scene graph.
+//
+// Scene tokens should be kept secret.
+//
+// TODO(jeffbrown): This implementation is a temporary placeholder until
+// we extend Mojo to provide a way to create tokens which cannot be forged.
+struct SceneToken {
+  uint32 value;
+};