compositing: Split non-WebView-specific data into ServoRenderer (#35536)

This will become the new global Servo renderer while each WebView will
also have its renderer (but not yet).

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Ngo Iok Ui (Wu Yu Wei) <yuweiwu@pm.me>

components/compositing/compositor.rs

@@ -96,17 +96,50 @@ impl FrameTreeId {
     }
 }
 
-/// NB: Never block on the constellation, because sometimes the constellation blocks on us.
-pub struct IOCompositor {
-    /// The application window.
-    pub window: Rc<dyn WindowMethods>,
-
-    /// The port on which we receive messages.
-    port: CompositorReceiver,
-
+/// Data that is shared by all WebView renderers.
+pub struct ServoRenderer {
     /// Our top-level browsing contexts.
     webviews: WebViewManager<WebView>,
 
+    /// Tracks whether we are in the process of shutting down, or have shut down and should close
+    /// the compositor.
+    shutdown_state: ShutdownState,
+
+    /// The port on which we receive messages.
+    compositor_receiver: CompositorReceiver,
+
+    /// The channel on which messages can be sent to the constellation.
+    constellation_sender: Sender<ConstellationMsg>,
+
+    /// The channel on which messages can be sent to the time profiler.
+    time_profiler_chan: profile_time::ProfilerChan,
+
+    /// The WebRender [`RenderApi`] interface used to communicate with WebRender.
+    webrender_api: RenderApi,
+
+    /// The GL bindings for webrender
+    webrender_gl: Rc<dyn gleam::gl::Gl>,
+
+    /// True to exit after page load ('-x').
+    exit_after_load: bool,
+
+    /// The string representing the version of Servo that is running. This is used to tag
+    /// WebRender capture output.
+    version_string: String,
+
+    #[cfg(feature = "webxr")]
+    /// Some XR devices want to run on the main thread.
+    webxr_main_thread: webxr::MainThreadRegistry,
+}
+
+/// NB: Never block on the constellation, because sometimes the constellation blocks on us.
+pub struct IOCompositor {
+    /// Data that is shared by all WebView renderers.
+    global: ServoRenderer,
+
+    /// The application window.
+    pub window: Rc<dyn WindowMethods>,
+
     /// Tracks details about each active pipeline that the compositor knows about.
     pipeline_details: HashMap<PipelineId, PipelineDetails>,
 
@@ -126,10 +159,6 @@ pub struct IOCompositor {
     /// Tracks whether or not the view needs to be repainted.
     needs_repaint: Cell<RepaintReason>,
 
-    /// Tracks whether we are in the process of shutting down, or have shut down and should close
-    /// the compositor.
-    pub shutdown_state: ShutdownState,
-
     /// Tracks whether the zoom action has happened recently.
     zoom_action: bool,
 
@@ -139,12 +168,6 @@ pub struct IOCompositor {
     /// The current frame tree ID (used to reject old paint buffers)
     frame_tree_id: FrameTreeId,
 
-    /// The channel on which messages can be sent to the constellation.
-    constellation_chan: Sender<ConstellationMsg>,
-
-    /// The channel on which messages can be sent to the time profiler.
-    time_profiler_chan: profile_time::ProfilerChan,
-
     /// Touch input state machine
     touch_handler: TouchHandler,
 
@@ -161,19 +184,9 @@ pub struct IOCompositor {
     /// The active webrender document.
     webrender_document: DocumentId,
 
-    /// The webrender interface, if enabled.
-    webrender_api: RenderApi,
-
     /// The surfman instance that webrender targets
     rendering_context: Rc<dyn RenderingContext>,
 
-    /// The GL bindings for webrender
-    webrender_gl: Rc<dyn gleam::gl::Gl>,
-
-    #[cfg(feature = "webxr")]
-    /// Some XR devices want to run on the main thread.
-    pub webxr_main_thread: webxr::MainThreadRegistry,
-
     /// A per-pipeline queue of display lists that have not yet been rendered by WebRender. Layout
     /// expects WebRender to paint each given epoch. Once the compositor paints a frame with that
     /// epoch's display list, it will be removed from the queue and the paint time will be recorded
@@ -190,9 +203,6 @@ pub struct IOCompositor {
     /// Current cursor position.
     cursor_pos: DevicePoint,
 
-    /// True to exit after page load ('-x').
-    exit_after_load: bool,
-
     /// True to translate mouse input into touch events.
     convert_mouse_to_touch: bool,
 
@@ -202,10 +212,6 @@ pub struct IOCompositor {
     /// The [`Instant`] of the last animation tick, used to avoid flooding the Constellation and
     /// ScriptThread with a deluge of animation ticks.
     last_animation_tick: Instant,
-
-    /// The string representing the version of Servo that is running. This is used to tag
-    /// WebRender capture output.
-    version_string: String,
 }
 
 #[derive(Clone, Copy)]
@@ -341,16 +347,26 @@ impl IOCompositor {
         version_string: String,
     ) -> Self {
         let compositor = IOCompositor {
+            global: ServoRenderer {
+                shutdown_state: ShutdownState::NotShuttingDown,
+                webviews: WebViewManager::default(),
+                compositor_receiver: state.receiver,
+                constellation_sender: state.constellation_chan,
+                time_profiler_chan: state.time_profiler_chan,
+                webrender_api: state.webrender_api,
+                webrender_gl: state.webrender_gl,
+                exit_after_load,
+                version_string,
+                #[cfg(feature = "webxr")]
+                webxr_main_thread: state.webxr_main_thread,
+            },
             embedder_coordinates: window.get_coordinates(),
             window,
-            port: state.receiver,
-            webviews: WebViewManager::default(),
             pipeline_details: HashMap::new(),
             needs_repaint: Cell::default(),
             touch_handler: TouchHandler::new(),
             pending_scroll_zoom_events: Vec::new(),
             composite_target,
-            shutdown_state: ShutdownState::NotShuttingDown,
             page_zoom: Scale::new(1.0),
             viewport_zoom: PinchZoomFactor::new(1.0),
             min_viewport_zoom: Some(PinchZoomFactor::new(1.0)),
@@ -358,33 +374,29 @@ impl IOCompositor {
             zoom_action: false,
             zoom_time: 0f64,
             frame_tree_id: FrameTreeId(0),
-            constellation_chan: state.constellation_chan,
-            time_profiler_chan: state.time_profiler_chan,
             ready_to_save_state: ReadyState::Unknown,
             webrender: Some(state.webrender),
             webrender_document: state.webrender_document,
-            webrender_api: state.webrender_api,
             rendering_context: state.rendering_context,
-            webrender_gl: state.webrender_gl,
-            #[cfg(feature = "webxr")]
-            webxr_main_thread: state.webxr_main_thread,
             pending_paint_metrics: HashMap::new(),
             cursor: Cursor::None,
             cursor_pos: DevicePoint::new(0.0, 0.0),
-            exit_after_load,
             convert_mouse_to_touch,
             pending_frames: 0,
             last_animation_tick: Instant::now(),
-            version_string,
         };
 
-        let gl = &compositor.webrender_gl;
+        let gl = &compositor.global.webrender_gl;
         info!("Running on {}", gl.get_string(gleam::gl::RENDERER));
         info!("OpenGL Version {}", gl.get_string(gleam::gl::VERSION));
         compositor.assert_gl_framebuffer_complete();
         compositor
     }
 
+    pub fn shutdown_state(&self) -> ShutdownState {
+        self.global.shutdown_state
+    }
+
     pub fn deinit(&mut self) {
         if let Err(err) = self.rendering_context.make_current() {
             warn!("Failed to make the rendering context current: {:?}", err);
@@ -424,23 +436,27 @@ impl IOCompositor {
 
         self.cursor = cursor;
         let msg = ConstellationMsg::SetCursor(webview_id, cursor);
-        if let Err(e) = self.constellation_chan.send(msg) {
+        if let Err(e) = self.global.constellation_sender.send(msg) {
             warn!("Sending event to constellation failed ({:?}).", e);
         }
     }
 
     pub fn start_shutting_down(&mut self) {
-        if self.shutdown_state != ShutdownState::NotShuttingDown {
+        if self.global.shutdown_state != ShutdownState::NotShuttingDown {
             warn!("Requested shutdown while already shutting down");
             return;
         }
 
         debug!("Compositor sending Exit message to Constellation");
-        if let Err(e) = self.constellation_chan.send(ConstellationMsg::Exit) {
+        if let Err(e) = self
+            .global
+            .constellation_sender
+            .send(ConstellationMsg::Exit)
+        {
             warn!("Sending exit message to constellation failed ({:?}).", e);
         }
 
-        self.shutdown_state = ShutdownState::ShuttingDown;
+        self.global.shutdown_state = ShutdownState::ShuttingDown;
     }
 
     fn finish_shutting_down(&mut self) {
@@ -448,22 +464,28 @@ impl IOCompositor {
 
         // Drain compositor port, sometimes messages contain channels that are blocking
         // another thread from finishing (i.e. SetFrameTree).
-        while self.port.try_recv_compositor_msg().is_some() {}
+        while self
+            .global
+            .compositor_receiver
+            .try_recv_compositor_msg()
+            .is_some()
+        {}
 
         // Tell the profiler, memory profiler, and scrolling timer to shut down.
         if let Ok((sender, receiver)) = ipc::channel() {
-            self.time_profiler_chan
+            self.global
+                .time_profiler_chan
                 .send(profile_time::ProfilerMsg::Exit(sender));
             let _ = receiver.recv();
         }
 
-        self.shutdown_state = ShutdownState::FinishedShuttingDown;
+        self.global.shutdown_state = ShutdownState::FinishedShuttingDown;
     }
 
     fn handle_browser_message(&mut self, msg: CompositorMsg) {
         trace_msg_from_constellation!(msg, "{msg:?}");
 
-        match self.shutdown_state {
+        match self.global.shutdown_state {
             ShutdownState::NotShuttingDown => {},
             ShutdownState::ShuttingDown => {
                 self.handle_browser_message_while_shutting_down(msg);
@@ -550,7 +572,7 @@ impl IOCompositor {
             CompositorMsg::LoadComplete(_) => {
                 // If we're painting in headless mode, schedule a recomposite.
                 if matches!(self.composite_target, CompositeTarget::PngFile(_)) ||
-                    self.exit_after_load
+                    self.global.exit_after_load
                 {
                     self.set_needs_repaint(RepaintReason::ReadyForScreenshot);
                 }
@@ -597,7 +619,8 @@ impl IOCompositor {
                 let mut txn = Transaction::new();
                 txn.set_display_list(WebRenderEpoch(0), (pipeline, Default::default()));
                 self.generate_frame(&mut txn, RenderReasons::SCENE);
-                self.webrender_api
+                self.global
+                    .webrender_api
                     .send_transaction(self.webrender_document, txn);
             },
 
@@ -633,7 +656,8 @@ impl IOCompositor {
                     }],
                 );
                 self.generate_frame(&mut txn, RenderReasons::APZ);
-                self.webrender_api
+                self.global
+                    .webrender_api
                     .send_transaction(self.webrender_document, txn);
             },
 
@@ -693,7 +717,8 @@ impl IOCompositor {
                     .set_display_list(display_list_info.epoch, (pipeline_id, built_display_list));
                 self.update_transaction_with_all_scroll_offsets(&mut transaction);
                 self.generate_frame(&mut transaction, RenderReasons::SCENE);
-                self.webrender_api
+                self.global
+                    .webrender_api
                     .send_transaction(self.webrender_document, transaction);
             },
 
@@ -708,14 +733,14 @@ impl IOCompositor {
                 // would be to listen to the TransactionNotifier for previous per-pipeline
                 // transactions, but that isn't easily compatible with the event loop wakeup
                 // mechanism from libserver.
-                self.webrender_api.flush_scene_builder();
+                self.global.webrender_api.flush_scene_builder();
 
                 let result = self.hit_test_at_point_with_flags_and_pipeline(point, flags, pipeline);
                 let _ = sender.send(result);
             },
 
             CrossProcessCompositorMessage::GenerateImageKey(sender) => {
-                let _ = sender.send(self.webrender_api.generate_image_key());
+                let _ = sender.send(self.global.webrender_api.generate_image_key());
             },
 
             CrossProcessCompositorMessage::UpdateImages(updates) => {
@@ -731,7 +756,8 @@ impl IOCompositor {
                         },
                     }
                 }
-                self.webrender_api
+                self.global
+                    .webrender_api
                     .send_transaction(self.webrender_document, txn);
             },
 
@@ -742,7 +768,8 @@ impl IOCompositor {
             CrossProcessCompositorMessage::AddSystemFont(font_key, native_handle) => {
                 let mut transaction = Transaction::new();
                 transaction.add_native_font(font_key, native_handle);
-                self.webrender_api
+                self.global
+                    .webrender_api
                     .send_transaction(self.webrender_document, transaction);
             },
 
@@ -765,14 +792,16 @@ impl IOCompositor {
                     transaction.delete_font(key);
                 }
 
-                self.webrender_api
+                self.global
+                    .webrender_api
                     .send_transaction(self.webrender_document, transaction);
             },
 
             CrossProcessCompositorMessage::AddImage(key, desc, data) => {
                 let mut txn = Transaction::new();
                 txn.add_image(key, desc, data.into(), None);
-                self.webrender_api
+                self.global
+                    .webrender_api
                     .send_transaction(self.webrender_document, txn);
             },
 
@@ -782,10 +811,10 @@ impl IOCompositor {
                 result_sender,
             ) => {
                 let font_keys = (0..number_of_font_keys)
-                    .map(|_| self.webrender_api.generate_font_key())
+                    .map(|_| self.global.webrender_api.generate_font_key())
                     .collect();
                 let font_instance_keys = (0..number_of_font_instance_keys)
-                    .map(|_| self.webrender_api.generate_font_instance_key())
+                    .map(|_| self.global.webrender_api.generate_font_instance_key())
                     .collect();
                 let _ = result_sender.send((font_keys, font_instance_keys));
             },
@@ -832,7 +861,7 @@ impl IOCompositor {
             CompositorMsg::CrossProcess(CrossProcessCompositorMessage::GenerateImageKey(
                 sender,
             )) => {
-                let _ = sender.send(self.webrender_api.generate_image_key());
+                let _ = sender.send(self.global.webrender_api.generate_image_key());
             },
             CompositorMsg::CrossProcess(CrossProcessCompositorMessage::GenerateFontKeys(
                 number_of_font_keys,
@@ -840,10 +869,10 @@ impl IOCompositor {
                 result_sender,
             )) => {
                 let font_keys = (0..number_of_font_keys)
-                    .map(|_| self.webrender_api.generate_font_key())
+                    .map(|_| self.global.webrender_api.generate_font_key())
                     .collect();
                 let font_instance_keys = (0..number_of_font_instance_keys)
-                    .map(|_| self.webrender_api.generate_font_instance_key())
+                    .map(|_| self.global.webrender_api.generate_font_instance_key())
                     .collect();
                 let _ = result_sender.send((font_keys, font_instance_keys));
             },
@@ -947,7 +976,8 @@ impl IOCompositor {
         let mut transaction = Transaction::new();
         self.send_root_pipeline_display_list_in_transaction(&mut transaction);
         self.generate_frame(&mut transaction, RenderReasons::SCENE);
-        self.webrender_api
+        self.global
+            .webrender_api
             .send_transaction(self.webrender_document, transaction);
     }
 
@@ -986,7 +1016,7 @@ impl IOCompositor {
 
         let root_clip_id = builder.define_clip_rect(zoom_reference_frame, scaled_viewport_rect);
         let clip_chain_id = builder.define_clip_chain(None, [root_clip_id]);
-        for (_, webview) in self.webviews.painting_order() {
+        for (_, webview) in self.global.webviews.painting_order() {
             if let Some(pipeline_id) = webview.pipeline_id {
                 let scaled_webview_rect = webview.rect / zoom_factor;
                 builder.push_iframe(
@@ -1042,7 +1072,7 @@ impl IOCompositor {
         debug!("{}: Setting frame tree for webview", frame_tree.pipeline.id);
 
         let top_level_browsing_context_id = frame_tree.pipeline.top_level_browsing_context_id;
-        if let Some(webview) = self.webviews.get_mut(top_level_browsing_context_id) {
+        if let Some(webview) = self.global.webviews.get_mut(top_level_browsing_context_id) {
             let new_pipeline_id = Some(frame_tree.pipeline.id);
             if new_pipeline_id != webview.pipeline_id {
                 debug!(
@@ -1058,7 +1088,7 @@ impl IOCompositor {
                 "{:?}: Creating new webview with pipeline {:?}",
                 top_level_browsing_context_id, pipeline_id
             );
-            if let Err(WebViewAlreadyExists(webview_id)) = self.webviews.add(
+            if let Err(WebViewAlreadyExists(webview_id)) = self.global.webviews.add(
                 top_level_browsing_context_id,
                 WebView {
                     pipeline_id,
@@ -1069,7 +1099,7 @@ impl IOCompositor {
                 return;
             }
             let msg = ConstellationMsg::WebViewOpened(top_level_browsing_context_id);
-            if let Err(e) = self.constellation_chan.send(msg) {
+            if let Err(e) = self.global.constellation_sender.send(msg) {
                 warn!("Sending event to constellation failed ({:?}).", e);
             }
         }
@@ -1083,7 +1113,7 @@ impl IOCompositor {
 
     fn remove_webview(&mut self, top_level_browsing_context_id: TopLevelBrowsingContextId) {
         debug!("{}: Removing", top_level_browsing_context_id);
-        let Ok(webview) = self.webviews.remove(top_level_browsing_context_id) else {
+        let Ok(webview) = self.global.webviews.remove(top_level_browsing_context_id) else {
             warn!("{top_level_browsing_context_id}: Removing unknown webview");
             return;
         };
@@ -1100,7 +1130,7 @@ impl IOCompositor {
         debug!("{webview_id}: Moving and/or resizing webview; rect={rect:?}");
         let rect_changed;
         let size_changed;
-        match self.webviews.get_mut(webview_id) {
+        match self.global.webviews.get_mut(webview_id) {
             Some(webview) => {
                 rect_changed = rect != webview.rect;
                 size_changed = rect.size() != webview.rect.size();
@@ -1129,15 +1159,16 @@ impl IOCompositor {
         debug!("{webview_id}: Showing webview; hide_others={hide_others}");
         let painting_order_changed = if hide_others {
             let result = self
+                .global
                 .webviews
                 .painting_order()
                 .map(|(&id, _)| id)
                 .ne(once(webview_id));
-            self.webviews.hide_all();
-            self.webviews.show(webview_id)?;
+            self.global.webviews.hide_all();
+            self.global.webviews.show(webview_id)?;
             result
         } else {
-            self.webviews.show(webview_id)?
+            self.global.webviews.show(webview_id)?
         };
         if painting_order_changed {
             self.send_root_pipeline_display_list();
@@ -1147,7 +1178,7 @@ impl IOCompositor {
 
     pub fn hide_webview(&mut self, webview_id: WebViewId) -> Result<(), UnknownWebView> {
         debug!("{webview_id}: Hiding webview");
-        if self.webviews.hide(webview_id)? {
+        if self.global.webviews.hide(webview_id)? {
             self.send_root_pipeline_display_list();
         }
         Ok(())
@@ -1161,15 +1192,16 @@ impl IOCompositor {
         debug!("{webview_id}: Raising webview to top; hide_others={hide_others}");
         let painting_order_changed = if hide_others {
             let result = self
+                .global
                 .webviews
                 .painting_order()
                 .map(|(&id, _)| id)
                 .ne(once(webview_id));
-            self.webviews.hide_all();
-            self.webviews.raise_to_top(webview_id)?;
+            self.global.webviews.hide_all();
+            self.global.webviews.raise_to_top(webview_id)?;
             result
         } else {
-            self.webviews.raise_to_top(webview_id)?
+            self.global.webviews.raise_to_top(webview_id)?
         };
         if painting_order_changed {
             self.send_root_pipeline_display_list();
@@ -1194,7 +1226,7 @@ impl IOCompositor {
             },
             WindowSizeType::Resize,
         );
-        if let Err(e) = self.constellation_chan.send(msg) {
+        if let Err(e) = self.global.constellation_sender.send(msg) {
             warn!("Sending window resize to constellation failed ({:?}).", e);
         }
     }
@@ -1267,7 +1299,7 @@ impl IOCompositor {
     }
 
     pub fn on_rendering_context_resized(&mut self) -> bool {
-        if self.shutdown_state != ShutdownState::NotShuttingDown {
+        if self.global.shutdown_state != ShutdownState::NotShuttingDown {
             return false;
         }
 
@@ -1279,7 +1311,8 @@ impl IOCompositor {
             let size = self.embedder_coordinates.get_viewport();
             transaction.set_document_view(size);
             self.rendering_context.resize(size.size().to_untyped());
-            self.webrender_api
+            self.global
+                .webrender_api
                 .send_transaction(self.webrender_document, transaction);
         }
 
@@ -1310,7 +1343,8 @@ impl IOCompositor {
         self.update_cursor(&result);
 
         if let Err(error) = self
-            .constellation_chan
+            .global
+            .constellation_sender
             .send(ConstellationMsg::ForwardInputEvent(event, Some(result)))
         {
             warn!("Sending event to constellation failed ({error:?}).");
@@ -1318,7 +1352,7 @@ impl IOCompositor {
     }
 
     pub fn on_input_event(&mut self, event: InputEvent) {
-        if self.shutdown_state != ShutdownState::NotShuttingDown {
+        if self.global.shutdown_state != ShutdownState::NotShuttingDown {
             return;
         }
 
@@ -1377,9 +1411,12 @@ impl IOCompositor {
     ) -> Vec<CompositorHitTestResult> {
         // DevicePoint and WorldPoint are the same for us.
         let world_point = WorldPoint::from_untyped(point.to_untyped());
-        let results =
-            self.webrender_api
-                .hit_test(self.webrender_document, pipeline_id, world_point, flags);
+        let results = self.global.webrender_api.hit_test(
+            self.webrender_document,
+            pipeline_id,
+            world_point,
+            flags,
+        );
 
         results
             .items
@@ -1419,7 +1456,8 @@ impl IOCompositor {
 
         let event = InputEvent::Touch(event);
         if let Err(e) = self
-            .constellation_chan
+            .global
+            .constellation_sender
             .send(ConstellationMsg::ForwardInputEvent(event, Some(result)))
         {
             warn!("Sending event to constellation failed ({:?}).", e);
@@ -1427,7 +1465,7 @@ impl IOCompositor {
     }
 
     pub fn on_touch_event(&mut self, event: TouchEvent) {
-        if self.shutdown_state != ShutdownState::NotShuttingDown {
+        if self.global.shutdown_state != ShutdownState::NotShuttingDown {
             return;
         }
 
@@ -1567,7 +1605,7 @@ impl IOCompositor {
         cursor: DeviceIntPoint,
         event_type: TouchEventType,
     ) {
-        if self.shutdown_state != ShutdownState::NotShuttingDown {
+        if self.global.shutdown_state != ShutdownState::NotShuttingDown {
             return;
         }
 
@@ -1670,7 +1708,8 @@ impl IOCompositor {
         }
 
         self.generate_frame(&mut transaction, RenderReasons::APZ);
-        self.webrender_api
+        self.global
+            .webrender_api
             .send_transaction(self.webrender_document, transaction);
     }
 
@@ -1745,7 +1784,7 @@ impl IOCompositor {
             }
         }
         #[cfg(feature = "webxr")]
-        let webxr_running = self.webxr_main_thread.running();
+        let webxr_running = self.global.webxr_main_thread.running();
         #[cfg(not(feature = "webxr"))]
         let webxr_running = false;
         let animation_state = if pipeline_ids.is_empty() && !webxr_running {
@@ -1777,7 +1816,7 @@ impl IOCompositor {
         }
 
         let msg = ConstellationMsg::TickAnimation(pipeline_id, tick_type);
-        if let Err(e) = self.constellation_chan.send(msg) {
+        if let Err(e) = self.global.constellation_sender.send(msg) {
             warn!("Sending tick to constellation failed ({:?}).", e);
         }
     }
@@ -1800,7 +1839,7 @@ impl IOCompositor {
     }
 
     pub fn on_zoom_reset_window_event(&mut self) {
-        if self.shutdown_state != ShutdownState::NotShuttingDown {
+        if self.global.shutdown_state != ShutdownState::NotShuttingDown {
             return;
         }
 
@@ -1809,7 +1848,7 @@ impl IOCompositor {
     }
 
     pub fn on_zoom_window_event(&mut self, magnification: f32) {
-        if self.shutdown_state != ShutdownState::NotShuttingDown {
+        if self.global.shutdown_state != ShutdownState::NotShuttingDown {
             return;
         }
 
@@ -1819,7 +1858,7 @@ impl IOCompositor {
     }
 
     fn update_after_zoom_or_hidpi_change(&mut self) {
-        for (top_level_browsing_context_id, webview) in self.webviews.painting_order() {
+        for (top_level_browsing_context_id, webview) in self.global.webviews.painting_order() {
             self.send_window_size_message_for_top_level_browser_context(
                 webview.rect,
                 *top_level_browsing_context_id,
@@ -1832,7 +1871,7 @@ impl IOCompositor {
 
     /// Simulate a pinch zoom
     pub fn on_pinch_zoom_window_event(&mut self, magnification: f32) {
-        if self.shutdown_state != ShutdownState::NotShuttingDown {
+        if self.global.shutdown_state != ShutdownState::NotShuttingDown {
             return;
         }
 
@@ -1923,7 +1962,7 @@ impl IOCompositor {
                 // Pass the pipeline/epoch states to the constellation and check
                 // if it's safe to output the image.
                 let msg = ConstellationMsg::IsReadyToSaveImage(pipeline_epochs);
-                if let Err(e) = self.constellation_chan.send(msg) {
+                if let Err(e) = self.global.constellation_sender.send(msg) {
                     warn!("Sending ready to save to constellation failed ({:?}).", e);
                 }
                 self.ready_to_save_state = ReadyState::WaitingForConstellationReply;
@@ -1959,7 +1998,9 @@ impl IOCompositor {
         // Queue up any subsequent paints for animations.
         self.process_animations(true);
 
-        if matches!(self.composite_target, CompositeTarget::PngFile(_)) || self.exit_after_load {
+        if matches!(self.composite_target, CompositeTarget::PngFile(_)) ||
+            self.global.exit_after_load
+        {
             println!("Shutting down the Constellation after generating an output file or exit flag specified");
             self.start_shutting_down();
         }
@@ -1991,7 +2032,7 @@ impl IOCompositor {
         let wait_for_stable_image = matches!(
             target,
             CompositeTarget::SharedMemory | CompositeTarget::PngFile(_)
-        ) || self.exit_after_load;
+        ) || self.global.exit_after_load;
 
         if wait_for_stable_image {
             // The current image may be ready to output. However, if there are animations active,
@@ -2013,7 +2054,7 @@ impl IOCompositor {
         time_profile!(
             ProfilerCategory::Compositing,
             None,
-            self.time_profiler_chan.clone(),
+            self.global.time_profiler_chan.clone(),
             || {
                 trace!("Compositing");
 
@@ -2066,7 +2107,7 @@ impl IOCompositor {
                 time_profile!(
                     ProfilerCategory::ImageSaving,
                     None,
-                    self.time_profiler_chan.clone(),
+                    self.global.time_profiler_chan.clone(),
                     || match File::create(&*path) {
                         Ok(mut file) => {
                             if let Some(image) = self.rendering_context.read_to_image(Rect::new(
@@ -2157,7 +2198,7 @@ impl IOCompositor {
     }
 
     fn clear_background(&self) {
-        let gl = &self.webrender_gl;
+        let gl = &self.global.webrender_gl;
         self.assert_gl_framebuffer_complete();
 
         // Always clear the entire RenderingContext, regardless of how many WebViews there are
@@ -2175,15 +2216,16 @@ impl IOCompositor {
 
     #[track_caller]
     fn assert_no_gl_error(&self) {
-        debug_assert_eq!(self.webrender_gl.get_error(), gleam::gl::NO_ERROR);
+        debug_assert_eq!(self.global.webrender_gl.get_error(), gleam::gl::NO_ERROR);
     }
 
     #[track_caller]
     fn assert_gl_framebuffer_complete(&self) {
         debug_assert_eq!(
             (
-                self.webrender_gl.get_error(),
-                self.webrender_gl
+                self.global.webrender_gl.get_error(),
+                self.global
+                    .webrender_gl
                     .check_frame_buffer_status(gleam::gl::FRAMEBUFFER)
             ),
             (gleam::gl::NO_ERROR, gleam::gl::FRAMEBUFFER_COMPLETE)
@@ -2198,7 +2240,7 @@ 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 Some(msg) = self.port.try_recv_compositor_msg() {
+        while let Some(msg) = self.global.compositor_receiver.try_recv_compositor_msg() {
             match msg {
                 CompositorMsg::NewWebRenderFrameReady(..) if found_recomposite_msg => {
                     // Only take one of duplicate NewWebRendeFrameReady messages, but do subtract
@@ -2215,7 +2257,7 @@ impl IOCompositor {
         for msg in compositor_messages {
             self.handle_browser_message(msg);
 
-            if self.shutdown_state == ShutdownState::FinishedShuttingDown {
+            if self.global.shutdown_state == ShutdownState::FinishedShuttingDown {
                 return;
             }
         }
@@ -2226,7 +2268,7 @@ impl IOCompositor {
         tracing::instrument(skip_all, fields(servo_profiling = true), level = "trace")
     )]
     pub fn perform_updates(&mut self) -> bool {
-        if self.shutdown_state == ShutdownState::FinishedShuttingDown {
+        if self.global.shutdown_state == ShutdownState::FinishedShuttingDown {
             return false;
         }
 
@@ -2241,7 +2283,7 @@ impl IOCompositor {
 
         #[cfg(feature = "webxr")]
         // Run the WebXR main thread
-        self.webxr_main_thread.run_one_frame();
+        self.global.webxr_main_thread.run_one_frame();
 
         // The WebXR thread may make a different context current
         if let Err(err) = self.rendering_context.make_current() {
@@ -2250,7 +2292,7 @@ impl IOCompositor {
         if !self.pending_scroll_zoom_events.is_empty() {
             self.process_pending_scroll_events()
         }
-        self.shutdown_state != ShutdownState::FinishedShuttingDown
+        self.global.shutdown_state != ShutdownState::FinishedShuttingDown
     }
 
     pub fn pinch_zoom_level(&self) -> Scale<f32, DevicePixel, DevicePixel> {
@@ -2288,7 +2330,8 @@ impl IOCompositor {
 
         let mut txn = Transaction::new();
         self.generate_frame(&mut txn, RenderReasons::TESTING);
-        self.webrender_api
+        self.global
+            .webrender_api
             .send_transaction(self.webrender_document, txn);
     }
 
@@ -2313,12 +2356,13 @@ impl IOCompositor {
         };
 
         println!("Saving WebRender capture to {capture_path:?}");
-        self.webrender_api
+        self.global
+            .webrender_api
             .save_capture(capture_path.clone(), CaptureBits::all());
 
         let version_file_path = capture_path.join("servo-version.txt");
         if let Err(error) = File::create(version_file_path)
-            .and_then(|mut file| write!(file, "{}", self.version_string))
+            .and_then(|mut file| write!(file, "{}", self.global.version_string))
         {
             eprintln!("Unable to write servo version for WebRender Capture: {error:?}");
         }
@@ -2346,14 +2390,16 @@ impl IOCompositor {
             Vec::new(),
         );
 
-        self.webrender_api
+        self.global
+            .webrender_api
             .send_transaction(self.webrender_document, transaction);
     }
 
     fn add_font(&mut self, font_key: FontKey, index: u32, data: Arc<IpcSharedMemory>) {
         let mut transaction = Transaction::new();
         transaction.add_raw_font(font_key, (**data).into(), index);
-        self.webrender_api
+        self.global
+            .webrender_api
             .send_transaction(self.webrender_document, transaction);
     }
 }