Bridge Servo screenshot capture

crates/ely_servo_host/src/host.rs

@@ -256,6 +256,11 @@ pub struct KeyboardTextRequest {
     pub text: String,
 }
 
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct ScreenshotRequest {
+    pub webview_id: WebViewId,
+}
+
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub struct PermissionRequest {
     pub webview_id: WebViewId,
@@ -292,6 +297,11 @@ pub trait ServoHost {
 
     fn type_text(&mut self, request: KeyboardTextRequest) -> Result<(), ServoHostError>;
 
+    fn capture_screenshot(
+        &mut self,
+        request: ScreenshotRequest,
+    ) -> Result<RenderedFrame, ServoHostError>;
+
     fn set_permission(
         &mut self,
         request: PermissionRequest,