webdriver: Move NewWebView, FocusWebView, GetWindowSize, and SetWindowSize to servoshell (#37555)

Follow up to: https://github.com/servo/servo/pull/36714
Moving webdriver [context
commands](https://www.w3.org/TR/webdriver2/#contexts) to be handled in
embedder:

- [x] New Window command - `WebdriverCommandMsg::NewWebView`
- [x]  Switch To Window command - `WebdriverCommandMsg::FocusWebView`
- [x] Resizing commands

cc: @xiaochengh

---------

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

ports/servoshell/desktop/app_state.rs

@@ -19,7 +19,7 @@ use servo::webrender_api::units::{DeviceIntPoint, DeviceIntSize};
 use servo::{
     AllowOrDenyRequest, AuthenticationRequest, FilterPattern, FormControl, GamepadHapticEffectType,
     KeyboardEvent, LoadStatus, PermissionRequest, Servo, ServoDelegate, ServoError, SimpleDialog,
-    WebDriverCommandMsg, WebView, WebViewBuilder, WebViewDelegate,
+    WebDriverCommandMsg, WebDriverLoadStatus, WebView, WebViewBuilder, WebViewDelegate,
 };
 use url::Url;
 
@@ -37,6 +37,13 @@ pub(crate) enum AppState {
     ShuttingDown,
 }
 
+/// A collection of [`IpcSender`]s that are used to asynchronously communicate
+/// to a WebDriver server with information about application state.
+#[derive(Clone, Default)]
+struct WebDriverSenders {
+    pub load_status_senders: HashMap<WebViewId, IpcSender<WebDriverLoadStatus>>,
+}
+
 pub(crate) struct RunningAppState {
     /// A handle to the Servo instance of the [`RunningAppState`]. This is not stored inside
     /// `inner` so that we can keep a reference to Servo in order to spin the event loop,
@@ -48,6 +55,7 @@ pub(crate) struct RunningAppState {
     /// A [`Receiver`] for receiving commands from a running WebDriver server, if WebDriver
     /// was enabled.
     webdriver_receiver: Option<Receiver<WebDriverCommandMsg>>,
+    webdriver_senders: RefCell<WebDriverSenders>,
     inner: RefCell<RunningAppStateInner>,
 }
 
@@ -99,6 +107,7 @@ impl RunningAppState {
             servo,
             servoshell_preferences,
             webdriver_receiver,
+            webdriver_senders: RefCell::default(),
             inner: RefCell::new(RunningAppStateInner {
                 webviews: HashMap::default(),
                 creation_order: Default::default(),
@@ -112,7 +121,13 @@ impl RunningAppState {
         }
     }
 
-    pub(crate) fn new_toplevel_webview(self: &Rc<Self>, url: Url) {
+    pub(crate) fn create_and_focus_toplevel_webview(self: &Rc<Self>, url: Url) {
+        let webview = self.create_toplevel_webview(url);
+        webview.focus();
+        webview.raise_to_top(true);
+    }
+
+    pub(crate) fn create_toplevel_webview(self: &Rc<Self>, url: Url) -> WebView {
         let webview = WebViewBuilder::new(self.servo())
             .url(url)
             .hidpi_scale_factor(self.inner().window.hidpi_scale_factor())
@@ -120,10 +135,8 @@ impl RunningAppState {
             .build();
 
         webview.notify_theme_change(self.inner().window.theme());
-        webview.focus();
-        webview.raise_to_top(true);
-
-        self.add(webview);
+        self.add(webview.clone());
+        webview
     }
 
     pub(crate) fn inner(&self) -> Ref<RunningAppStateInner> {
@@ -382,6 +395,17 @@ impl RunningAppState {
                 webview.notify_scroll_event(location, origin);
             });
     }
+
+    pub(crate) fn set_load_status_sender(
+        &self,
+        webview_id: WebViewId,
+        sender: IpcSender<WebDriverLoadStatus>,
+    ) {
+        self.webdriver_senders
+            .borrow_mut()
+            .load_status_senders
+            .insert(webview_id, sender);
+    }
 }
 
 struct ServoShellServoDelegate;
@@ -507,8 +531,19 @@ impl WebViewDelegate for RunningAppState {
         self.inner().window.set_cursor(cursor);
     }
 
-    fn notify_load_status_changed(&self, _webview: servo::WebView, _status: LoadStatus) {
+    fn notify_load_status_changed(&self, webview: servo::WebView, status: LoadStatus) {
         self.inner_mut().need_update = true;
+
+        if status == LoadStatus::Complete {
+            if let Some(sender) = self
+                .webdriver_senders
+                .borrow_mut()
+                .load_status_senders
+                .remove(&webview.id())
+            {
+                let _ = sender.send(WebDriverLoadStatus::Complete);
+            }
+        }
     }
 
     fn notify_fullscreen_state_changed(&self, _webview: servo::WebView, fullscreen_state: bool) {