Move `ScriptToConstellationMsg` to `constellation_traits` (#36364)

This is the last big change necessary to create the
`constellation_traits` crate. This moves the data structure for messages
that originate from the `ScriptThread` and are sent to the
`Contellation` to `constellation_traits`, effectively splitting
`script_traits` in half. Before, `script_traits` was responsible for
exposing the API of both the `ScriptThread` and the `Constellation` to
the rest of Servo.

- Data structures that are used by `ScriptToConstellationMsg` are moved
  to `constellation_traits`. The dependency graph looks a bit like this:
  `script_layout_interface` depends on `script_traits` depends on
  `constellation_traits` depends on `embedder_traits`.
- Data structures that are used in the embedding layer
  (`UntrustedNodeAddress`, `CompositorHitTestResult`, `TouchEventResult`
  and `AnimationState`) are moved to embedder_traits, to avoid a
  dependency cycle between `webrender_traits` and
  `constellation_traits`.
- Types dealing with MessagePorts and serialization are moved to
  `constellation_traits::message_port`.

Testing: This is covered by existing tests as it just moves types
around.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/components/layout_thread_2020/lib.rs b/components/layout_thread_2020/lib.rs
index a34a7bf75a5..9639275608b 100644
--- a/components/layout_thread_2020/lib.rs
+++ b/components/layout_thread_2020/lib.rs
@@ -17,9 +17,9 @@ use std::sync::{Arc, LazyLock};
 use app_units::Au;
 use base::Epoch;
 use base::id::{PipelineId, WebViewId};
-use constellation_traits::{ScrollState, UntrustedNodeAddress};
-use embedder_traits::ViewportDetails;
+use constellation_traits::ScrollState;
 use embedder_traits::resources::{self, Resource};
+use embedder_traits::{UntrustedNodeAddress, ViewportDetails};
 use euclid::default::{Point2D as UntypedPoint2D, Rect as UntypedRect, Size2D as UntypedSize2D};
 use euclid::{Point2D, Scale, Size2D, Vector2D};
 use fnv::FnvHashMap;