webdriver: Get the window position as well as the size when resolving "Get Window Rect" (#37812)

1. Rename `GetWindowSize` to `GetWindowRect`
2. Return the WindowRect in device pixels correctly. Previously, it
returns `(0, 0, ScreenWidth, ScreenHeight)` which is a static value.
3. Add `fn window_rect` to `WindowPortsMethods`. Implement it for both
Headless Window and Headed Window.

Testing: Tested manually with powershell script. Result is now dynamic
and reflects the truth.
Fixes: Task 1 & 2 of https://github.com/servo/servo/issues/37804

---------

Signed-off-by: Euclid Ye <yezhizhenjiakang@gmail.com>

ports/servoshell/desktop/app.rs

@@ -362,14 +362,14 @@ impl App {
                     // TODO: send a response to the WebDriver
                     // so it knows when the focus has finished.
                 },
-                WebDriverCommandMsg::GetWindowSize(_webview_id, response_sender) => {
+                WebDriverCommandMsg::GetWindowRect(_webview_id, response_sender) => {
                     let window = self
                         .windows
                         .values()
                         .next()
                         .expect("Should have at least one window in servoshell");
 
-                    if let Err(error) = response_sender.send(window.screen_geometry().size) {
+                    if let Err(error) = response_sender.send(window.window_rect()) {
                         warn!("Failed to send response of GetWindowSize: {error}");
                     }
                 },

ports/servoshell/desktop/headed_window.rs

@@ -17,7 +17,7 @@ use raw_window_handle::{HasDisplayHandle, HasWindowHandle, RawWindowHandle};
 use servo::servo_config::pref;
 use servo::servo_geometry::DeviceIndependentPixel;
 use servo::webrender_api::ScrollLocation;
-use servo::webrender_api::units::{DeviceIntPoint, DeviceIntSize, DevicePixel};
+use servo::webrender_api::units::{DeviceIntPoint, DeviceIntRect, DeviceIntSize, DevicePixel};
 use servo::{
     Cursor, ImeEvent, InputEvent, Key, KeyState, KeyboardEvent, MouseButton as ServoMouseButton,
     MouseButtonAction, MouseButtonEvent, MouseLeaveEvent, MouseMoveEvent,
@@ -483,6 +483,17 @@ impl WindowPortsMethods for Window {
             })
     }
 
+    fn window_rect(&self) -> DeviceIntRect {
+        let outer_size = self.winit_window.outer_size();
+        let total_size = Size2D::new(outer_size.width as i32, outer_size.height as i32);
+        let origin = self
+            .winit_window
+            .outer_position()
+            .map(|point| Point2D::new(point.x, point.y))
+            .unwrap_or_default();
+        DeviceIntRect::from_origin_and_size(origin, total_size)
+    }
+
     fn set_position(&self, point: DeviceIntPoint) {
         self.winit_window
             .set_outer_position::<PhysicalPosition<i32>>(PhysicalPosition::new(point.x, point.y))

ports/servoshell/desktop/headless_window.rs

@@ -8,9 +8,9 @@ use std::cell::Cell;
 use std::rc::Rc;
 
 use euclid::num::Zero;
-use euclid::{Length, Scale, Size2D};
+use euclid::{Length, Point2D, Scale, Size2D};
 use servo::servo_geometry::DeviceIndependentPixel;
-use servo::webrender_api::units::{DeviceIntSize, DevicePixel};
+use servo::webrender_api::units::{DeviceIntRect, DeviceIntSize, DevicePixel};
 use servo::{RenderingContext, ScreenGeometry, SoftwareRenderingContext};
 use winit::dpi::PhysicalSize;
 
@@ -135,6 +135,10 @@ impl WindowPortsMethods for Window {
         Length::zero()
     }
 
+    fn window_rect(&self) -> DeviceIntRect {
+        DeviceIntRect::from_origin_and_size(Point2D::zero(), self.inner_size.get())
+    }
+
     fn set_toolbar_height(&self, _height: Length<f32, DeviceIndependentPixel>) {
         unimplemented!("headless Window only")
     }

ports/servoshell/desktop/window_trait.rs

@@ -9,7 +9,7 @@ use std::rc::Rc;
 
 use euclid::{Length, Scale};
 use servo::servo_geometry::DeviceIndependentPixel;
-use servo::webrender_api::units::{DeviceIntPoint, DeviceIntSize, DevicePixel};
+use servo::webrender_api::units::{DeviceIntPoint, DeviceIntRect, DeviceIntSize, DevicePixel};
 use servo::{Cursor, RenderingContext, ScreenGeometry, WebView};
 
 use super::app_state::RunningAppState;
@@ -52,4 +52,5 @@ pub trait WindowPortsMethods {
     fn theme(&self) -> servo::Theme {
         servo::Theme::Light
     }
+    fn window_rect(&self) -> DeviceIntRect;
 }