Auto merge of #20071 - paulrouget:typedsize, r=glennw

Use typed coordinates more

Requires https://github.com/servo/servo/pull/19895

We use Size2D and Point2D across compositing, constellation and script, loosing the type of pixels we use (DevicePixel, DeviceIndepententPixel or CSSPixel) along the way, which might lead to bugs like `window.outerHeight` not taking into account the page zoom (using DeviceIndepententPixel instead of CSSPixel).

This should make the situation a bit better.

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- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

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components/servo/lib.rs

@@ -81,6 +81,7 @@ use constellation::{FromCompositorLogger, FromScriptLogger};
 #[cfg(all(not(target_os = "windows"), not(target_os = "ios")))]
 use constellation::content_process_sandbox_profile;
 use env_logger::Logger as EnvLogger;
+use euclid::Length;
 #[cfg(all(not(target_os = "windows"), not(target_os = "ios")))]
 use gaol::sandbox::{ChildSandbox, ChildSandboxMethods};
 use gfx::font_cache_thread::FontCacheThread;
@@ -133,7 +134,7 @@ impl<Window> Servo<Window> where Window: WindowMethods + 'static {
         let opts = opts::get();
 
         // Make sure the gl context is made current.
-        window.prepare_for_composite(0, 0);
+        window.prepare_for_composite(Length::new(0), Length::new(0));
 
         // Get both endpoints of a special channel for communication between
         // the client window and the compositor. This channel is unique because