Make Mozart view manager use the new compositor.

mojo/services/ui/views/interfaces/layouts.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.ui;
 
 import "mojo/services/geometry/interfaces/geometry.mojom";
-import "mojo/services/surfaces/interfaces/surface_id.mojom";
+import "mojo/services/gfx/composition/interfaces/scene_token.mojom";
 
 // Box constraints for layout.
 //
 // A box constraint allows a parent view to determine the size of its child
 // by constraining its width and height.  Each dimension is considered
 // independently.  If a constraint only admits a single value in one or both
 // dimensions (because the minimum and maximum values are equal) then it is
 // said to be "tight" in those dimension.
 //
 // A |Size| respects this constraint if, and only if, all of the following
@@ skipping 38 matching lines @@
 
   // The ratio between the size of one display device pixel to the size
   // of one logical pixel, assuming pixels are square.  This value changes
   // in relation to display density and zoom level.
   // Must be > 0.
   float device_pixel_ratio = 1.0;
 };
 
 // Layout information for a view.
 struct ViewLayoutInfo {
-  // The view's surface id for composition by the parent.
-  mojo.SurfaceId surface_id;
+  // The view's scene token for composition by the parent.
+  mojo.gfx.composition.SceneToken scene_token;
 
   // The actual size of the view in device pixels.
   mojo.Size size;
 };
+
+// Result of a view layout request.
+struct ViewLayoutResult {
+  // The actual size of the view in device pixels.
+  mojo.Size size;
+};