Revert "compositor: Unify the cross process and in-process API (#36443)" (#36533)

This reverts commit 4c55104b36.

This commit introduced an issue where messages from script to the
compositor no longer woke up the embedder. There is a larger issue
here, but this change exacerbated it.

Fixes #36528.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

components/compositing/compositor.rs

@@ -19,7 +19,8 @@ use bitflags::bitflags;
 use compositing_traits::display_list::{CompositorDisplayListInfo, HitTestInfo, ScrollTree};
 use compositing_traits::rendering_context::RenderingContext;
 use compositing_traits::{
-    CompositionPipeline, CompositorMsg, ImageUpdate, RendererWebView, SendableFrameTree,
+    CompositionPipeline, CompositorMsg, CompositorReceiver, CrossProcessCompositorMessage,
+    ImageUpdate, RendererWebView, SendableFrameTree,
 };
 use constellation_traits::{AnimationTickType, EmbedderToConstellationMessage, PaintMetricEvent};
 use crossbeam_channel::Sender;
@@ -30,7 +31,7 @@ use embedder_traits::{
 };
 use euclid::{Point2D, Rect, Scale, Size2D, Transform3D};
 use fnv::FnvHashMap;
-use ipc_channel::ipc::{self, IpcReceiver, IpcSharedMemory};
+use ipc_channel::ipc::{self, IpcSharedMemory};
 use libc::c_void;
 use log::{debug, info, trace, warn};
 use pixels::{CorsStatus, Image, ImageFrame, PixelFormat};
@@ -89,7 +90,7 @@ pub struct ServoRenderer {
     shutdown_state: Rc<Cell<ShutdownState>>,
 
     /// The port on which we receive messages.
-    compositor_receiver: IpcReceiver<CompositorMsg>,
+    compositor_receiver: CompositorReceiver,
 
     /// The channel on which messages can be sent to the constellation.
     pub(crate) constellation_sender: Sender<EmbedderToConstellationMessage>,
@@ -466,8 +467,8 @@ impl IOCompositor {
             .global
             .borrow_mut()
             .compositor_receiver
-            .try_recv()
-            .is_ok()
+            .try_recv_compositor_msg()
+            .is_some()
         {}
 
         // Tell the profiler, memory profiler, and scrolling timer to shut down.
@@ -629,14 +630,33 @@ impl IOCompositor {
                 webview.dispatch_input_event(InputEvent::MouseMove(MouseMoveEvent { point }));
             },
 
-            CompositorMsg::SendInitialTransaction(pipeline) => {
+            CompositorMsg::CrossProcess(cross_proces_message) => {
+                self.handle_cross_process_message(cross_proces_message);
+            },
+        }
+    }
+
+    /// Accept messages from content processes that need to be relayed to the WebRender
+    /// instance in the parent process.
+    #[cfg_attr(
+        feature = "tracing",
+        tracing::instrument(skip_all, fields(servo_profiling = true), level = "trace")
+    )]
+    fn handle_cross_process_message(&mut self, msg: CrossProcessCompositorMessage) {
+        match msg {
+            CrossProcessCompositorMessage::SendInitialTransaction(pipeline) => {
                 let mut txn = Transaction::new();
                 txn.set_display_list(WebRenderEpoch(0), (pipeline, Default::default()));
                 self.generate_frame(&mut txn, RenderReasons::SCENE);
                 self.global.borrow_mut().send_transaction(txn);
             },
 
-            CompositorMsg::SendScrollNode(webview_id, pipeline_id, point, external_scroll_id) => {
+            CrossProcessCompositorMessage::SendScrollNode(
+                webview_id,
+                pipeline_id,
+                point,
+                external_scroll_id,
+            ) => {
                 let Some(webview) = self.webviews.get_mut(webview_id) else {
                     return;
                 };
@@ -670,7 +690,7 @@ impl IOCompositor {
                 self.global.borrow_mut().send_transaction(txn);
             },
 
-            CompositorMsg::SendDisplayList {
+            CrossProcessCompositorMessage::SendDisplayList {
                 webview_id,
                 display_list_descriptor,
                 display_list_receiver,
@@ -759,7 +779,7 @@ impl IOCompositor {
                 self.global.borrow_mut().send_transaction(transaction);
             },
 
-            CompositorMsg::HitTest(pipeline, point, flags, sender) => {
+            CrossProcessCompositorMessage::HitTest(pipeline, point, flags, sender) => {
                 // When a display list is sent to WebRender, it starts scene building in a
                 // separate thread and then that display list is available for hit testing.
                 // Without flushing scene building, any hit test we do might be done against
@@ -785,11 +805,11 @@ impl IOCompositor {
                 let _ = sender.send(result);
             },
 
-            CompositorMsg::GenerateImageKey(sender) => {
+            CrossProcessCompositorMessage::GenerateImageKey(sender) => {
                 let _ = sender.send(self.global.borrow().webrender_api.generate_image_key());
             },
 
-            CompositorMsg::UpdateImages(updates) => {
+            CrossProcessCompositorMessage::UpdateImages(updates) => {
                 let mut txn = Transaction::new();
                 for update in updates {
                     match update {
@@ -805,21 +825,26 @@ impl IOCompositor {
                 self.global.borrow_mut().send_transaction(txn);
             },
 
-            CompositorMsg::AddFont(font_key, data, index) => {
+            CrossProcessCompositorMessage::AddFont(font_key, data, index) => {
                 self.add_font(font_key, index, data);
             },
 
-            CompositorMsg::AddSystemFont(font_key, native_handle) => {
+            CrossProcessCompositorMessage::AddSystemFont(font_key, native_handle) => {
                 let mut transaction = Transaction::new();
                 transaction.add_native_font(font_key, native_handle);
                 self.global.borrow_mut().send_transaction(transaction);
             },
 
-            CompositorMsg::AddFontInstance(font_instance_key, font_key, size, flags) => {
+            CrossProcessCompositorMessage::AddFontInstance(
+                font_instance_key,
+                font_key,
+                size,
+                flags,
+            ) => {
                 self.add_font_instance(font_instance_key, font_key, size, flags);
             },
 
-            CompositorMsg::RemoveFonts(keys, instance_keys) => {
+            CrossProcessCompositorMessage::RemoveFonts(keys, instance_keys) => {
                 let mut transaction = Transaction::new();
 
                 for instance in instance_keys.into_iter() {
@@ -832,13 +857,13 @@ impl IOCompositor {
                 self.global.borrow_mut().send_transaction(transaction);
             },
 
-            CompositorMsg::AddImage(key, desc, data) => {
+            CrossProcessCompositorMessage::AddImage(key, desc, data) => {
                 let mut txn = Transaction::new();
                 txn.add_image(key, desc, data.into(), None);
                 self.global.borrow_mut().send_transaction(txn);
             },
 
-            CompositorMsg::GenerateFontKeys(
+            CrossProcessCompositorMessage::GenerateFontKeys(
                 number_of_font_keys,
                 number_of_font_instance_keys,
                 result_sender,
@@ -856,7 +881,7 @@ impl IOCompositor {
                     .collect();
                 let _ = result_sender.send((font_keys, font_instance_keys));
             },
-            CompositorMsg::GetClientWindowRect(webview_id, response_sender) => {
+            CrossProcessCompositorMessage::GetClientWindowRect(webview_id, response_sender) => {
                 let client_window_rect = self
                     .webviews
                     .get(webview_id)
@@ -866,7 +891,7 @@ impl IOCompositor {
                     warn!("Sending response to get client window failed ({error:?}).");
                 }
             },
-            CompositorMsg::GetScreenSize(webview_id, response_sender) => {
+            CrossProcessCompositorMessage::GetScreenSize(webview_id, response_sender) => {
                 let screen_size = self
                     .webviews
                     .get(webview_id)
@@ -876,7 +901,7 @@ impl IOCompositor {
                     warn!("Sending response to get screen size failed ({error:?}).");
                 }
             },
-            CompositorMsg::GetAvailableScreenSize(webview_id, response_sender) => {
+            CrossProcessCompositorMessage::GetAvailableScreenSize(webview_id, response_sender) => {
                 let available_screen_size = self
                     .webviews
                     .get(webview_id)
@@ -910,14 +935,16 @@ impl IOCompositor {
                 }
                 let _ = sender.send(());
             },
-            CompositorMsg::GenerateImageKey(sender) => {
+            CompositorMsg::CrossProcess(CrossProcessCompositorMessage::GenerateImageKey(
+                sender,
+            )) => {
                 let _ = sender.send(self.global.borrow().webrender_api.generate_image_key());
             },
-            CompositorMsg::GenerateFontKeys(
+            CompositorMsg::CrossProcess(CrossProcessCompositorMessage::GenerateFontKeys(
                 number_of_font_keys,
                 number_of_font_instance_keys,
                 result_sender,
-            ) => {
+            )) => {
                 let font_keys = (0..number_of_font_keys)
                     .map(|_| self.global.borrow().webrender_api.generate_font_key())
                     .collect();
@@ -931,17 +958,26 @@ impl IOCompositor {
                     .collect();
                 let _ = result_sender.send((font_keys, font_instance_keys));
             },
-            CompositorMsg::GetClientWindowRect(_, response_sender) => {
+            CompositorMsg::CrossProcess(CrossProcessCompositorMessage::GetClientWindowRect(
+                _,
+                response_sender,
+            )) => {
                 if let Err(error) = response_sender.send(Default::default()) {
                     warn!("Sending response to get client window failed ({error:?}).");
                 }
             },
-            CompositorMsg::GetScreenSize(_, response_sender) => {
+            CompositorMsg::CrossProcess(CrossProcessCompositorMessage::GetScreenSize(
+                _,
+                response_sender,
+            )) => {
                 if let Err(error) = response_sender.send(Default::default()) {
                     warn!("Sending response to get client window failed ({error:?}).");
                 }
             },
-            CompositorMsg::GetAvailableScreenSize(_, response_sender) => {
+            CompositorMsg::CrossProcess(CrossProcessCompositorMessage::GetAvailableScreenSize(
+                _,
+                response_sender,
+            )) => {
                 if let Err(error) = response_sender.send(Default::default()) {
                     warn!("Sending response to get client window failed ({error:?}).");
                 }
@@ -1564,7 +1600,12 @@ impl IOCompositor {
         // Check for new messages coming from the other threads in the system.
         let mut compositor_messages = vec![];
         let mut found_recomposite_msg = false;
-        while let Ok(msg) = self.global.borrow_mut().compositor_receiver.try_recv() {
+        while let Some(msg) = self
+            .global
+            .borrow_mut()
+            .compositor_receiver
+            .try_recv_compositor_msg()
+        {
             match msg {
                 CompositorMsg::NewWebRenderFrameReady(..) if found_recomposite_msg => {
                     // Only take one of duplicate NewWebRendeFrameReady messages, but do subtract