Use non-IPC webrender API over explicit IPC channels.

components/canvas/lib.rs

@@ -4,6 +4,10 @@
 
 #![deny(unsafe_code)]
 
+use canvas_traits::canvas::CanvasId;
+use crossbeam_channel::Sender;
+use euclid::default::Size2D;
+
 #[macro_use]
 extern crate bitflags;
 #[macro_use]
@@ -22,3 +26,13 @@ pub mod canvas_paint_thread;
 mod webgl_limits;
 mod webgl_mode;
 pub mod webgl_thread;
+
+pub enum ConstellationCanvasMsg {
+    Create {
+        id_sender: Sender<CanvasId>,
+        size: Size2D<u64>,
+        webrender_sender: webrender_api::RenderApiSender,
+        antialias: bool,
+    },
+    Exit,
+}