webdriver: Implement support for simple dialogs (#37913)

Implement webdriver user prompt: accept alert, dismiss alert, get alert
text.

Tests:
https://github.com/longvatrong111/servo/actions/runs/16175408035
https://github.com/longvatrong111/servo/actions/runs/16175409545

Signed-off-by: batu_hoang <longvatrong111@gmail.com>

components/shared/embedder/lib.rs

@@ -160,6 +160,59 @@ pub enum SimpleDialog {
     },
 }
 
+impl SimpleDialog {
+    /// Returns the message of the dialog.
+    pub fn message(&self) -> &str {
+        match self {
+            SimpleDialog::Alert { message, .. } => message,
+            SimpleDialog::Confirm { message, .. } => message,
+            SimpleDialog::Prompt { message, .. } => message,
+        }
+    }
+
+    pub fn dismiss(&self) {
+        match self {
+            SimpleDialog::Alert {
+                response_sender, ..
+            } => {
+                let _ = response_sender.send(AlertResponse::Ok);
+            },
+            SimpleDialog::Confirm {
+                response_sender, ..
+            } => {
+                let _ = response_sender.send(ConfirmResponse::Cancel);
+            },
+            SimpleDialog::Prompt {
+                response_sender, ..
+            } => {
+                let _ = response_sender.send(PromptResponse::Cancel);
+            },
+        }
+    }
+
+    pub fn accept(&self) {
+        match self {
+            SimpleDialog::Alert {
+                response_sender, ..
+            } => {
+                let _ = response_sender.send(AlertResponse::Ok);
+            },
+            SimpleDialog::Confirm {
+                response_sender, ..
+            } => {
+                let _ = response_sender.send(ConfirmResponse::Ok);
+            },
+            SimpleDialog::Prompt {
+                default,
+                response_sender,
+                ..
+            } => {
+                let _ = response_sender.send(PromptResponse::Ok(default.clone()));
+            },
+        }
+    }
+}
+
 #[derive(Debug, Default, Deserialize, PartialEq, Serialize)]
 pub struct AuthenticationResponse {
     /// Username for http request authentication

components/shared/embedder/webdriver.rs

@@ -28,6 +28,12 @@ use crate::{MouseButton, MouseButtonAction};
 #[derive(Clone, Copy, Debug, Deserialize, PartialEq, Serialize)]
 pub struct WebDriverMessageId(pub usize);
 
+#[derive(Debug, Deserialize, Serialize)]
+pub enum WebDriverUserPromptAction {
+    Accept,
+    Dismiss,
+}
+
 /// Messages to the constellation originating from the WebDriver server.
 #[derive(Debug, Deserialize, Serialize)]
 pub enum WebDriverCommandMsg {
@@ -115,6 +121,12 @@ pub enum WebDriverCommandMsg {
     IsWebViewOpen(WebViewId, IpcSender<bool>),
     /// Check whether browsing context is open.
     IsBrowsingContextOpen(BrowsingContextId, IpcSender<bool>),
+    HandleUserPrompt(
+        WebViewId,
+        WebDriverUserPromptAction,
+        IpcSender<Result<(), ()>>,
+    ),
+    GetAlertText(WebViewId, IpcSender<Result<String, ()>>),
 }
 
 #[derive(Debug, Deserialize, Serialize)]
@@ -237,4 +249,5 @@ pub enum WebDriverLoadStatus {
     Complete,
     Timeout,
     Canceled,
+    Blocked,
 }