libservo: Start moving WindowMethods to WebViewDelegate (#36223)

`WindowMethods` is used by the embedding layer to get information from
the embedder. This change moves the functionality for getting screen
size and `WebView` offsets to `WebViewDelegate`.

This is important because `WebView`s might be on different screens or
have different offsets on the screen itself, so it makes sense for this
to be per-`WebView` and not global to the embedder. HiDPI and animation
state functionality will move to the embedder in subsequent changes.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

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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 do not require tests because they just modify the
`WebView` API surface a bit.

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Signed-off-by: Martin Robinson <mrobinson@igalia.com>

ports/servoshell/desktop/app.rs

@@ -11,13 +11,16 @@ use std::rc::Rc;
 use std::time::Instant;
 use std::{env, fs};
 
+use euclid::Scale;
 use log::{info, trace, warn};
 use servo::compositing::windowing::{AnimationState, WindowMethods};
 use servo::config::opts::Opts;
 use servo::config::prefs::Preferences;
 use servo::servo_config::pref;
+use servo::servo_geometry::DeviceIndependentPixel;
 use servo::servo_url::ServoUrl;
 use servo::user_content_manager::{UserContentManager, UserScript};
+use servo::webrender_api::units::DevicePixel;
 use servo::webxr::glwindow::GlWindowDiscovery;
 #[cfg(target_os = "windows")]
 use servo::webxr::openxr::{AppInfo, OpenXrDiscovery};
@@ -140,8 +143,8 @@ impl App {
         // <https://github.com/rust-lang/rust/issues/65991>
         struct UpcastedWindow(Rc<dyn WindowPortsMethods>);
         impl WindowMethods for UpcastedWindow {
-            fn get_coordinates(&self) -> servo::compositing::windowing::EmbedderCoordinates {
-                self.0.get_coordinates()
+            fn hidpi_factor(&self) -> Scale<f32, DeviceIndependentPixel, DevicePixel> {
+                self.0.hidpi_factor()
             }
             fn set_animation_state(&self, state: AnimationState) {
                 self.0.set_animation_state(state);