servo: Merge #17916 - Use AntialiasMode in CanvasPaintThread::new (from DarkDrek:Use_AntialiasMode_in_CanvasPaintThread_new); r=emilio

Change suggested in #17661

<!-- Please describe your changes on the following line: -->
I only changed `canvas_paint_thread.rs` since `CanvasPaintThread::start` is used outside of the current crate and `azure::azure_hl::AntialiasMode` isn't available there.

---
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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 #17661 (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [X] These changes do not require tests because @jdm said so

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Source-Repo: https://github.com/servo/servo
Source-Revision: 0337ebb5a936a5fefb69a552c9d54b084f21ddc2

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : d4e8d9634126158a71114ae17f5dd76f44d4ac8c

servo/components/canvas/canvas_paint_thread.rs

@@ -80,13 +80,7 @@ struct CanvasPaintState<'a> {
 }
 
 impl<'a> CanvasPaintState<'a> {
-    fn new(antialias: bool) -> CanvasPaintState<'a> {
+    fn new(antialias: AntialiasMode) -> CanvasPaintState<'a> {
-        let antialias = if antialias {
-            AntialiasMode::Default
-        } else {
-            AntialiasMode::None
-        };
-
         CanvasPaintState {
             draw_options: DrawOptions::new(1.0, CompositionOp::Over, antialias),
             fill_style: Pattern::Color(ColorPattern::new(Color::black())),
@@ -104,7 +98,7 @@ impl<'a> CanvasPaintState<'a> {
 impl<'a> CanvasPaintThread<'a> {
     fn new(size: Size2D<i32>,
            webrender_api_sender: webrender_api::RenderApiSender,
-           antialias: bool) -> CanvasPaintThread<'a> {
+           antialias: AntialiasMode) -> CanvasPaintThread<'a> {
         let draw_target = CanvasPaintThread::create(size);
         let path_builder = draw_target.create_path_builder();
         let webrender_api = webrender_api_sender.create_api();
@@ -127,6 +121,11 @@ impl<'a> CanvasPaintThread<'a> {
                  antialias: bool)
                  -> IpcSender<CanvasMsg> {
         let (sender, receiver) = ipc::channel::<CanvasMsg>().unwrap();
+        let antialias = if antialias {
+            AntialiasMode::Default
+        } else {
+            AntialiasMode::None
+        };
         thread::Builder::new().name("CanvasThread".to_owned()).spawn(move || {
             let mut painter = CanvasPaintThread::new(size, webrender_api_sender, antialias);
             loop {
@@ -550,7 +549,7 @@ impl<'a> CanvasPaintThread<'a> {
 
     fn recreate(&mut self, size: Size2D<i32>) {
         self.drawtarget = CanvasPaintThread::create(size);
-        self.state = CanvasPaintState::new(self.state.draw_options.antialias == AntialiasMode::Default);
+        self.state = CanvasPaintState::new(self.state.draw_options.antialias);
         self.saved_states.clear();
         // Webrender doesn't let images change size, so we clear the webrender image key.
         if let Some(image_key) = self.image_key.take() {