Auto merge of #11270 - servo:ConstellationChan, r=asajeffrey

Remove ConstellationChan.

Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data:
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy --faster` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

Either:
- [ ] There are tests for these changes OR
- [x] These changes do not require tests because _____

Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process.

It's a pointless abstraction that propagates the obsolete chan terminology,
swaps the order in which the sender and receiver are returned, and hides a
source of panics.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11270)
<!-- Reviewable:end -->

1 files changed, 3 insertions, 4 deletions

diff --git a/components/script/layout_interface.rs b/components/script/layout_interface.rs
index 2a9598fcc8b..2a6e0b1d79a 100644
--- a/components/script/layout_interface.rs
+++ b/components/script/layout_interface.rs
@@ -12,8 +12,7 @@ use euclid::point::Point2D;
 use euclid::rect::Rect;
 use gfx_traits::{Epoch, LayerId};
 use ipc_channel::ipc::{IpcReceiver, IpcSender};
-use msg::constellation_msg::{ConstellationChan, PanicMsg, PipelineId};
-use msg::constellation_msg::{WindowSizeData};
+use msg::constellation_msg::{PanicMsg, PipelineId, WindowSizeData};
 use net_traits::image_cache_thread::ImageCacheThread;
 use profile_traits::mem::ReportsChan;
 use script_traits::{ConstellationControlMsg, LayoutControlMsg, LayoutMsg as ConstellationMsg};
@@ -262,8 +261,8 @@ pub struct NewLayoutThreadInfo {
     pub is_parent: bool,
     pub layout_pair: OpaqueScriptLayoutChannel,
     pub pipeline_port: IpcReceiver<LayoutControlMsg>,
-    pub constellation_chan: ConstellationChan<ConstellationMsg>,
-    pub panic_chan: ConstellationChan<PanicMsg>,
+    pub constellation_chan: IpcSender<ConstellationMsg>,
+    pub panic_chan: IpcSender<PanicMsg>,
     pub script_chan: IpcSender<ConstellationControlMsg>,
     pub image_cache_thread: ImageCacheThread,
     pub paint_chan: OptionalOpaqueIpcSender,