Auto merge of #25694 - kunalmohan:24891-Constellation, r=Manishearth

Remove dependency of constellation on canvas

move `ConstellationCanvasMsg` to canvas_traits and start canvas paint thread
to components/servo. This, however, does not remove dependency for conditional
compilation options.

https://github.com/servo/servo/blob/5f55cd5d71df9c555fbc24777168396ddd539f28/components/constellation/Cargo.toml#L13-L15

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- [X] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [X] These changes fix #24891  (GitHub issue number if applicable)

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- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because ___

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1 files changed, 14 insertions, 0 deletions

diff --git a/components/canvas_traits/lib.rs b/components/canvas_traits/lib.rs
index c19ca073658..d7d893b2b32 100644
--- a/components/canvas_traits/lib.rs
+++ b/components/canvas_traits/lib.rs
@@ -6,6 +6,10 @@
 #![crate_type = "rlib"]
 #![deny(unsafe_code)]
 
+use crate::canvas::CanvasId;
+use crossbeam_channel::Sender;
+use euclid::default::Size2D;
+
 #[macro_use]
 extern crate lazy_static;
 #[macro_use]
@@ -17,3 +21,13 @@ pub mod canvas;
 #[macro_use]
 pub mod webgl;
 mod webgl_channel;
+
+pub enum ConstellationCanvasMsg {
+    Create {
+        id_sender: Sender<CanvasId>,
+        size: Size2D<u64>,
+        webrender_sender: webrender_api::RenderApiSender,
+        antialias: bool,
+    },
+    Exit,
+}