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>

components/constellation/constellation.rs

@@ -4534,7 +4534,7 @@ where
                 let is_open = self.browsing_contexts.contains_key(&browsing_context_id);
                 let _ = response_sender.send(is_open);
             },
-            WebDriverCommandMsg::GetWindowSize(..) => {
+            WebDriverCommandMsg::GetWindowRect(..) => {
                 unreachable!("This command should be send directly to the embedder.");
             },
             WebDriverCommandMsg::GetViewportSize(..) => {

components/shared/embedder/webdriver.rs

@@ -20,7 +20,7 @@ use servo_url::ServoUrl;
 use style_traits::CSSPixel;
 use webdriver::common::{WebElement, WebFrame, WebWindow};
 use webdriver::error::ErrorStatus;
-use webrender_api::units::{DeviceIntSize, DevicePixel};
+use webrender_api::units::{DeviceIntRect, DeviceIntSize, DevicePixel};
 
 use crate::{MouseButton, MouseButtonAction};
 
@@ -31,7 +31,7 @@ pub struct WebDriverMessageId(pub usize);
 #[derive(Debug, Deserialize, Serialize)]
 pub enum WebDriverCommandMsg {
     /// Get the window size.
-    GetWindowSize(WebViewId, IpcSender<Size2D<i32, DevicePixel>>),
+    GetWindowRect(WebViewId, IpcSender<DeviceIntRect>),
     /// Get the viewport size.
     GetViewportSize(WebViewId, IpcSender<Size2D<u32, DevicePixel>>),
     /// Load a URL in the top-level browsing context with the given ID.

components/webdriver_server/lib.rs

@@ -799,7 +799,7 @@ impl Handler {
     }
 
     /// <https://w3c.github.io/webdriver/#get-window-rect>
-    fn handle_window_size(
+    fn handle_window_rect(
         &self,
         verify: VerifyBrowsingContextIsOpen,
     ) -> WebDriverResult<WebDriverResponse> {
@@ -810,14 +810,14 @@ impl Handler {
         if let VerifyBrowsingContextIsOpen::Yes = verify {
             self.verify_top_level_browsing_context_is_open(webview_id)?;
         }
-        self.send_message_to_embedder(WebDriverCommandMsg::GetWindowSize(webview_id, sender))?;
+        self.send_message_to_embedder(WebDriverCommandMsg::GetWindowRect(webview_id, sender))?;
 
-        let window_size = wait_for_script_response(receiver)?;
+        let window_rect = wait_for_script_response(receiver)?;
         let window_size_response = WindowRectResponse {
-            x: 0,
-            y: 0,
-            width: window_size.width,
-            height: window_size.height,
+            x: window_rect.min.x,
+            y: window_rect.min.y,
+            width: window_rect.width(),
+            height: window_rect.height(),
         };
         Ok(WebDriverResponse::WindowRect(window_size_response))
     }
@@ -842,7 +842,7 @@ impl Handler {
         // We don't current allow modifying the window x/y positions, so we can just
         // return the current window rectangle if not changing dimension.
         if params.width.is_none() && params.height.is_none() {
-            return self.handle_window_size(VerifyBrowsingContextIsOpen::No);
+            return self.handle_window_rect(VerifyBrowsingContextIsOpen::No);
         }
         // (TODO) Step 14. Fully exit fullscreen.
         // (TODO) Step 15. Restore the window.
@@ -853,7 +853,7 @@ impl Handler {
 
         let current = LazyCell::new(|| {
             let WebDriverResponse::WindowRect(current) = self
-                .handle_window_size(VerifyBrowsingContextIsOpen::No)
+                .handle_window_rect(VerifyBrowsingContextIsOpen::No)
                 .unwrap()
             else {
                 unreachable!("handle_window_size() must return WindowRect");
@@ -2160,7 +2160,7 @@ impl WebDriverHandler<ServoExtensionRoute> for Handler {
             WebDriverCommand::Get(ref parameters) => self.handle_get(parameters),
             WebDriverCommand::GetCurrentUrl => self.handle_current_url(),
             WebDriverCommand::GetWindowRect => {
-                self.handle_window_size(VerifyBrowsingContextIsOpen::Yes)
+                self.handle_window_rect(VerifyBrowsingContextIsOpen::Yes)
             },
             WebDriverCommand::SetWindowRect(ref size) => self.handle_set_window_size(size),
             WebDriverCommand::IsEnabled(ref element) => self.handle_is_enabled(element),