Desktop: Isolate CEF-rendered UI into separate crate and process (#4321)

* Extract CEF rendered UI into a separate process and crate

* Review

* Review

* Review

* Review

* Remove necessary workarounds

* Block on frame copy ack

* Crop and resample frames correctly

* Skip blank frames

* Fix deps

* Fix fmt

* Fix clippy warning

* Review

* Fix todo

desktop/ui/src/delegate.rs

@@ -0,0 +1,59 @@
+use ipc_channel::ipc::IpcSender;
+use std::path::PathBuf;
+use std::sync::mpsc::Receiver;
+use std::sync::{Arc, Mutex};
+
+use super::remote::messages::EventMessage;
+use super::view::{ViewInfo, ViewInfoReceiver, ViewInfoUpdate};
+use crate::Cursor;
+
+#[derive(Clone)]
+pub(crate) struct BrowserDelegate(Arc<Inner>);
+
+struct Inner {
+	sender: Arc<Mutex<IpcSender<EventMessage>>>,
+	view_info: Mutex<ViewInfoReceiver>,
+}
+
+impl BrowserDelegate {
+	pub(crate) fn new(sender: Arc<Mutex<IpcSender<EventMessage>>>, view_info_receiver: Receiver<ViewInfoUpdate>) -> Self {
+		Self(Arc::new(Inner {
+			sender,
+			view_info: Mutex::new(ViewInfoReceiver::new(view_info_receiver)),
+		}))
+	}
+
+	fn send(&self, message: EventMessage) {
+		let Ok(sender) = self.0.sender.lock() else {
+			tracing::error!("Failed to lock host message sender");
+			return;
+		};
+		if let Err(e) = sender.send(message) {
+			tracing::debug!("Failed to send message to main process: {e}");
+		}
+	}
+
+	pub(crate) fn view_info(&self) -> ViewInfo {
+		let Ok(mut guard) = self.0.view_info.lock() else {
+			tracing::error!("Failed to lock the view info mirror");
+			return ViewInfo::new();
+		};
+		guard.current()
+	}
+
+	pub(crate) fn load_resource(&self, path: PathBuf) -> Option<crate::resources::Resource> {
+		crate::resources::load(path)
+	}
+
+	pub(crate) fn cursor_change(&self, cursor: Cursor) {
+		self.send(EventMessage::CursorChange(cursor));
+	}
+
+	pub(crate) fn initialized_web_communication(&self) {
+		self.send(EventMessage::WebCommunicationInitialized);
+	}
+
+	pub(crate) fn receive_web_message(&self, message: &[u8]) {
+		self.send(EventMessage::WebMessage(message.to_vec()));
+	}
+}