diff --git a/components/layout_thread/lib.rs b/components/layout_thread/lib.rs
index d7d59f5a152..f941cc6a8bb 100644
--- a/components/layout_thread/lib.rs
+++ b/components/layout_thread/lib.rs
@@ -62,12 +62,10 @@ use profile_traits::time::{
     self as profile_time, profile, TimerMetadata, TimerMetadataFrameType, TimerMetadataReflowType,
 };
 use script::layout_dom::{ServoLayoutDocument, ServoLayoutElement, ServoLayoutNode};
-use script_layout_interface::message::{
-    Msg, NodesFromPointQueryType, Reflow, ReflowComplete, ReflowGoal, ScriptReflow,
-};
 use script_layout_interface::wrapper_traits::LayoutNode;
 use script_layout_interface::{
-    Layout, LayoutConfig, LayoutFactory, OffsetParentResponse, TrustedNodeAddress,
+    Layout, LayoutConfig, LayoutFactory, NodesFromPointQueryType, OffsetParentResponse, Reflow,
+    ReflowComplete, ReflowGoal, ScriptReflow, TrustedNodeAddress,
 };
 use script_traits::{
     ConstellationControlMsg, DrawAPaintImageResult, IFrameSizeMsg, LayoutControlMsg,
@@ -252,10 +250,6 @@ impl Drop for ScriptReflowResult {
 }
 
 impl Layout for LayoutThread {
-    fn process(&mut self, msg: script_layout_interface::message::Msg) {
-        self.handle_request(Request::FromScript(msg));
-    }
-
     fn handle_constellation_msg(&mut self, msg: script_traits::LayoutControlMsg) {
         self.handle_request(Request::FromPipeline(msg));
     }
@@ -470,10 +464,94 @@ impl Layout for LayoutThread {
         );
         self.indexable_text.borrow().text_index(node, point_in_node)
     }
+
+    fn exit_now(&mut self) {
+        // Drop the root flow explicitly to avoid holding style data, such as
+        // rule nodes.  The `Stylist` checks when it is dropped that all rule
+        // nodes have been GCed, so we want drop anyone who holds them first.
+        let waiting_time_min = self.layout_query_waiting_time.minimum().unwrap_or(0);
+        let waiting_time_max = self.layout_query_waiting_time.maximum().unwrap_or(0);
+        let waiting_time_mean = self.layout_query_waiting_time.mean().unwrap_or(0);
+        let waiting_time_stddev = self.layout_query_waiting_time.stddev().unwrap_or(0);
+        debug!(
+            "layout: query waiting time: min: {}, max: {}, mean: {}, standard_deviation: {}",
+            waiting_time_min, waiting_time_max, waiting_time_mean, waiting_time_stddev
+        );
+
+        self.root_flow.borrow_mut().take();
+    }
+
+    fn set_quirks_mode(&mut self, quirks_mode: QuirksMode) {
+        self.stylist.set_quirks_mode(quirks_mode);
+    }
+
+    fn register_paint_worklet_modules(
+        &mut self,
+        name: Atom,
+        mut properties: Vec<Atom>,
+        painter: Box<dyn Painter>,
+    ) {
+        debug!("Registering the painter");
+        let properties = properties
+            .drain(..)
+            .filter_map(|name| {
+                let id = PropertyId::parse_enabled_for_all_content(&*name).ok()?;
+                Some((name.clone(), id))
+            })
+            .filter(|&(_, ref id)| !id.is_shorthand())
+            .collect();
+        let registered_painter = RegisteredPainterImpl {
+            name: name.clone(),
+            properties,
+            painter,
+        };
+        self.registered_painters.0.insert(name, registered_painter);
+    }
+
+    fn collect_reports(&self, reports_chan: ReportsChan) {
+        let mut reports = vec![];
+        // Servo uses vanilla jemalloc, which doesn't have a
+        // malloc_enclosing_size_of function.
+        let mut ops = MallocSizeOfOps::new(servo_allocator::usable_size, None, None);
+
+        // FIXME(njn): Just measuring the display tree for now.
+        let display_list = self.display_list.borrow();
+        let display_list_ref = display_list.as_ref();
+        let formatted_url = &format!("url({})", self.url);
+        reports.push(Report {
+            path: path![formatted_url, "layout-thread", "display-list"],
+            kind: ReportKind::ExplicitJemallocHeapSize,
+            size: display_list_ref.map_or(0, |sc| sc.size_of(&mut ops)),
+        });
+
+        reports.push(Report {
+            path: path![formatted_url, "layout-thread", "stylist"],
+            kind: ReportKind::ExplicitJemallocHeapSize,
+            size: self.stylist.size_of(&mut ops),
+        });
+
+        // The LayoutThread has data in Persistent TLS...
+        reports.push(Report {
+            path: path![formatted_url, "layout-thread", "local-context"],
+            kind: ReportKind::ExplicitJemallocHeapSize,
+            size: malloc_size_of_persistent_local_context(&mut ops),
+        });
+
+        reports_chan.send(reports);
+    }
+
+    fn reflow(&mut self, script_reflow: script_layout_interface::ScriptReflow) {
+        let mut result = ScriptReflowResult::new(script_reflow);
+        profile(
+            profile_time::ProfilerCategory::LayoutPerform,
+            self.profiler_metadata(),
+            self.time_profiler_chan.clone(),
+            || self.handle_reflow(&mut result),
+        );
+    }
 }
 enum Request {
     FromPipeline(LayoutControlMsg),
-    FromScript(Msg),
     FromFontCache,
 }
 
@@ -610,114 +688,18 @@ impl LayoutThread {
     /// Receives and dispatches messages from the script and constellation threads
     fn handle_request(&mut self, request: Request) {
         match request {
-            Request::FromPipeline(LayoutControlMsg::SetScrollStates(new_scroll_states)) => {
-                self.handle_request_helper(Msg::SetScrollStates(new_scroll_states))
-            },
-            Request::FromPipeline(LayoutControlMsg::ExitNow) => {
-                self.handle_request_helper(Msg::ExitNow);
-            },
-            Request::FromPipeline(LayoutControlMsg::PaintMetric(epoch, paint_time)) => {
-                self.paint_time_metrics.maybe_set_metric(epoch, paint_time);
-            },
-            Request::FromScript(msg) => self.handle_request_helper(msg),
             Request::FromFontCache => {
                 self.outstanding_web_fonts.fetch_sub(1, Ordering::SeqCst);
                 self.handle_web_font_loaded();
             },
-        };
-    }
-
-    /// Receives and dispatches messages from other threads.
-    fn handle_request_helper(&mut self, request: Msg) {
-        match request {
-            Msg::SetQuirksMode(mode) => self.handle_set_quirks_mode(mode),
-            Msg::Reflow(data) => {
-                let mut data = ScriptReflowResult::new(data);
-                profile(
-                    profile_time::ProfilerCategory::LayoutPerform,
-                    self.profiler_metadata(),
-                    self.time_profiler_chan.clone(),
-                    || self.handle_reflow(&mut data),
-                );
-            },
-            Msg::SetScrollStates(new_scroll_states) => {
+            Request::FromPipeline(LayoutControlMsg::ExitNow) => self.exit_now(),
+            Request::FromPipeline(LayoutControlMsg::SetScrollStates(new_scroll_states)) => {
                 self.set_scroll_states(new_scroll_states);
             },
-            Msg::CollectReports(reports_chan) => {
-                self.collect_reports(reports_chan);
+            Request::FromPipeline(LayoutControlMsg::PaintMetric(epoch, paint_time)) => {
+                self.paint_time_metrics.maybe_set_metric(epoch, paint_time);
             },
-            Msg::RegisterPaint(name, mut properties, painter) => {
-                debug!("Registering the painter");
-                let properties = properties
-                    .drain(..)
-                    .filter_map(|name| {
-                        let id = PropertyId::parse_enabled_for_all_content(&*name).ok()?;
-                        Some((name.clone(), id))
-                    })
-                    .filter(|&(_, ref id)| !id.is_shorthand())
-                    .collect();
-                let registered_painter = RegisteredPainterImpl {
-                    name: name.clone(),
-                    properties,
-                    painter,
-                };
-                self.registered_painters.0.insert(name, registered_painter);
-            },
-            // Receiving the Exit message at this stage only happens when layout is undergoing a "force exit".
-            Msg::ExitNow => {
-                debug!("layout: ExitNow received");
-                self.exit_now();
-            },
-        }
-    }
-
-    fn collect_reports(&self, reports_chan: ReportsChan) {
-        let mut reports = vec![];
-        // Servo uses vanilla jemalloc, which doesn't have a
-        // malloc_enclosing_size_of function.
-        let mut ops = MallocSizeOfOps::new(servo_allocator::usable_size, None, None);
-
-        // FIXME(njn): Just measuring the display tree for now.
-        let display_list = self.display_list.borrow();
-        let display_list_ref = display_list.as_ref();
-        let formatted_url = &format!("url({})", self.url);
-        reports.push(Report {
-            path: path![formatted_url, "layout-thread", "display-list"],
-            kind: ReportKind::ExplicitJemallocHeapSize,
-            size: display_list_ref.map_or(0, |sc| sc.size_of(&mut ops)),
-        });
-
-        reports.push(Report {
-            path: path![formatted_url, "layout-thread", "stylist"],
-            kind: ReportKind::ExplicitJemallocHeapSize,
-            size: self.stylist.size_of(&mut ops),
-        });
-
-        // The LayoutThread has data in Persistent TLS...
-        reports.push(Report {
-            path: path![formatted_url, "layout-thread", "local-context"],
-            kind: ReportKind::ExplicitJemallocHeapSize,
-            size: malloc_size_of_persistent_local_context(&mut ops),
-        });
-
-        reports_chan.send(reports);
-    }
-
-    /// Shuts down layout now.
-    fn exit_now(&mut self) {
-        // Drop the root flow explicitly to avoid holding style data, such as
-        // rule nodes.  The `Stylist` checks when it is dropped that all rule
-        // nodes have been GCed, so we want drop anyone who holds them first.
-        let waiting_time_min = self.layout_query_waiting_time.minimum().unwrap_or(0);
-        let waiting_time_max = self.layout_query_waiting_time.maximum().unwrap_or(0);
-        let waiting_time_mean = self.layout_query_waiting_time.mean().unwrap_or(0);
-        let waiting_time_stddev = self.layout_query_waiting_time.stddev().unwrap_or(0);
-        debug!(
-            "layout: query waiting time: min: {}, max: {}, mean: {}, standard_deviation: {}",
-            waiting_time_min, waiting_time_max, waiting_time_mean, waiting_time_stddev
-        );
-
-        self.root_flow.borrow_mut().take();
+        };
     }
 
     fn load_all_web_fonts_from_stylesheet_with_guard(
@@ -753,11 +735,6 @@ impl LayoutThread {
             .unwrap();
     }
 
-    /// Sets quirks mode for the document, causing the quirks mode stylesheet to be used.
-    fn handle_set_quirks_mode(&mut self, quirks_mode: QuirksMode) {
-        self.stylist.set_quirks_mode(quirks_mode);
-    }
-
     fn try_get_layout_root<'dom>(&self, node: impl LayoutNode<'dom>) -> Option<FlowRef> {
         let result = node
             .to_threadsafe()
diff --git a/components/layout_thread_2020/lib.rs b/components/layout_thread_2020/lib.rs
index 49d08e6b4cb..1b9e1498d42 100644
--- a/components/layout_thread_2020/lib.rs
+++ b/components/layout_thread_2020/lib.rs
@@ -48,11 +48,9 @@ use profile_traits::time::{
     self as profile_time, profile, TimerMetadata, TimerMetadataFrameType, TimerMetadataReflowType,
 };
 use script::layout_dom::{ServoLayoutDocument, ServoLayoutElement, ServoLayoutNode};
-use script_layout_interface::message::{
-    Msg, NodesFromPointQueryType, ReflowComplete, ReflowGoal, ScriptReflow,
-};
 use script_layout_interface::{
-    Layout, LayoutConfig, LayoutFactory, OffsetParentResponse, TrustedNodeAddress,
+    Layout, LayoutConfig, LayoutFactory, NodesFromPointQueryType, OffsetParentResponse,
+    ReflowComplete, ReflowGoal, ScriptReflow, TrustedNodeAddress,
 };
 use script_traits::{
     ConstellationControlMsg, DrawAPaintImageResult, IFrameSizeMsg, LayoutControlMsg,
@@ -227,10 +225,6 @@ impl Drop for ScriptReflowResult {
 }
 
 impl Layout for LayoutThread {
-    fn process(&mut self, msg: script_layout_interface::message::Msg) {
-        self.handle_request(Request::FromScript(msg));
-    }
-
     fn handle_constellation_msg(&mut self, msg: script_traits::LayoutControlMsg) {
         self.handle_request(Request::FromPipeline(msg));
     }
@@ -420,11 +414,57 @@ impl Layout for LayoutThread {
         );
         process_text_index_request(node, point_in_node)
     }
+
+    fn exit_now(&mut self) {}
+
+    fn collect_reports(&self, reports_chan: ReportsChan) {
+        let mut reports = vec![];
+        // Servo uses vanilla jemalloc, which doesn't have a
+        // malloc_enclosing_size_of function.
+        let mut ops = MallocSizeOfOps::new(servo_allocator::usable_size, None, None);
+
+        // FIXME(njn): Just measuring the display tree for now.
+        let formatted_url = &format!("url({})", self.url);
+        reports.push(Report {
+            path: path![formatted_url, "layout-thread", "display-list"],
+            kind: ReportKind::ExplicitJemallocHeapSize,
+            size: 0,
+        });
+
+        reports.push(Report {
+            path: path![formatted_url, "layout-thread", "stylist"],
+            kind: ReportKind::ExplicitJemallocHeapSize,
+            size: self.stylist.size_of(&mut ops),
+        });
+
+        reports_chan.send(reports);
+    }
+
+    fn set_quirks_mode(&mut self, quirks_mode: QuirksMode) {
+        self.stylist.set_quirks_mode(quirks_mode);
+    }
+
+    fn reflow(&mut self, script_reflow: ScriptReflow) {
+        let mut result = ScriptReflowResult::new(script_reflow);
+        profile(
+            profile_time::ProfilerCategory::LayoutPerform,
+            self.profiler_metadata(),
+            self.time_profiler_chan.clone(),
+            || self.handle_reflow(&mut result),
+        );
+    }
+
+    fn register_paint_worklet_modules(
+        &mut self,
+        _name: Atom,
+        _properties: Vec<Atom>,
+        _painter: Box<dyn Painter>,
+    ) {
+    }
 }
 
 enum Request {
     FromPipeline(LayoutControlMsg),
-    FromScript(Msg),
     FromFontCache,
 }
 
@@ -558,15 +598,12 @@ impl LayoutThread {
     fn handle_request(&mut self, request: Request) {
         match request {
             Request::FromPipeline(LayoutControlMsg::SetScrollStates(new_scroll_states)) => {
-                self.handle_request_helper(Msg::SetScrollStates(new_scroll_states))
-            },
-            Request::FromPipeline(LayoutControlMsg::ExitNow) => {
-                self.handle_request_helper(Msg::ExitNow);
+                self.set_scroll_states(new_scroll_states);
             },
+            Request::FromPipeline(LayoutControlMsg::ExitNow) => {},
             Request::FromPipeline(LayoutControlMsg::PaintMetric(epoch, paint_time)) => {
                 self.paint_time_metrics.maybe_set_metric(epoch, paint_time);
             },
-            Request::FromScript(msg) => self.handle_request_helper(msg),
             Request::FromFontCache => {
                 self.outstanding_web_fonts.fetch_sub(1, Ordering::SeqCst);
                 self.handle_web_font_loaded();
@@ -574,54 +611,6 @@ impl LayoutThread {
         };
     }
 
-    /// Receives and dispatches messages from other threads.
-    fn handle_request_helper(&mut self, request: Msg) {
-        match request {
-            Msg::SetQuirksMode(mode) => self.handle_set_quirks_mode(mode),
-            Msg::Reflow(data) => {
-                let mut data = ScriptReflowResult::new(data);
-                profile(
-                    profile_time::ProfilerCategory::LayoutPerform,
-                    self.profiler_metadata(),
-                    self.time_profiler_chan.clone(),
-                    || self.handle_reflow(&mut data),
-                );
-            },
-            Msg::SetScrollStates(new_scroll_states) => {
-                self.set_scroll_states(new_scroll_states);
-            },
-            Msg::CollectReports(reports_chan) => {
-                self.collect_reports(reports_chan);
-            },
-            Msg::RegisterPaint(_name, _properties, _painter) => {},
-            // Receiving the Exit message at this stage only happens when layout is undergoing a "force exit".
-            Msg::ExitNow => {},
-        }
-    }
-
-    fn collect_reports(&self, reports_chan: ReportsChan) {
-        let mut reports = vec![];
-        // Servo uses vanilla jemalloc, which doesn't have a
-        // malloc_enclosing_size_of function.
-        let mut ops = MallocSizeOfOps::new(servo_allocator::usable_size, None, None);
-
-        // FIXME(njn): Just measuring the display tree for now.
-        let formatted_url = &format!("url({})", self.url);
-        reports.push(Report {
-            path: path![formatted_url, "layout-thread", "display-list"],
-            kind: ReportKind::ExplicitJemallocHeapSize,
-            size: 0,
-        });
-
-        reports.push(Report {
-            path: path![formatted_url, "layout-thread", "stylist"],
-            kind: ReportKind::ExplicitJemallocHeapSize,
-            size: self.stylist.size_of(&mut ops),
-        });
-
-        reports_chan.send(reports);
-    }
-
     fn load_all_web_fonts_from_stylesheet_with_guard(
         &self,
         stylesheet: &Stylesheet,
@@ -657,11 +646,6 @@ impl LayoutThread {
             .unwrap();
     }
 
-    /// Sets quirks mode for the document, causing the quirks mode stylesheet to be used.
-    fn handle_set_quirks_mode(&mut self, quirks_mode: QuirksMode) {
-        self.stylist.set_quirks_mode(quirks_mode);
-    }
-
     /// The high-level routine that performs layout.
     fn handle_reflow(&mut self, data: &mut ScriptReflowResult) {
         let document = unsafe { ServoLayoutNode::new(&data.document) };
diff --git a/components/script/dom/activation.rs b/components/script/dom/activation.rs
index 0880d1fdb64..f337560dbfe 100644
--- a/components/script/dom/activation.rs
+++ b/components/script/dom/activation.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use script_layout_interface::message::ReflowGoal;
+use script_layout_interface::ReflowGoal;
 
 use crate::dom::element::Element;
 use crate::dom::event::Event;
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index c66b82619ea..8ac19c20244 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -44,8 +44,7 @@ use num_traits::ToPrimitive;
 use percent_encoding::percent_decode;
 use profile_traits::ipc as profile_ipc;
 use profile_traits::time::{TimerMetadata, TimerMetadataFrameType, TimerMetadataReflowType};
-use script_layout_interface::message::{Msg, PendingRestyle, ReflowGoal};
-use script_layout_interface::TrustedNodeAddress;
+use script_layout_interface::{PendingRestyle, ReflowGoal, TrustedNodeAddress};
 use script_traits::{
     AnimationState, DocumentActivity, MouseButton, MouseEventType, MsDuration, ScriptMsg,
     TouchEventType, TouchId, UntrustedNodeAddress, WheelDelta,
@@ -841,7 +840,7 @@ impl Document {
         if old_mode != new_mode {
             let _ = self
                 .window
-                .with_layout(move |layout| layout.process(Msg::SetQuirksMode(new_mode)));
+                .with_layout(move |layout| layout.set_quirks_mode(new_mode));
         }
     }
 
diff --git a/components/script/dom/documentorshadowroot.rs b/components/script/dom/documentorshadowroot.rs
index 59e84acf13c..25ada1eddae 100644
--- a/components/script/dom/documentorshadowroot.rs
+++ b/components/script/dom/documentorshadowroot.rs
@@ -5,7 +5,7 @@
 use std::fmt;
 
 use euclid::default::Point2D;
-use script_layout_interface::message::{NodesFromPointQueryType, QueryMsg};
+use script_layout_interface::{NodesFromPointQueryType, QueryMsg};
 use script_traits::UntrustedNodeAddress;
 use servo_arc::Arc;
 use servo_atoms::Atom;
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index e6879bb17e6..8edf819325c 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -28,7 +28,7 @@ use js::rust::HandleObject;
 use msg::constellation_msg::InputMethodType;
 use net_traits::request::CorsSettings;
 use net_traits::ReferrerPolicy;
-use script_layout_interface::message::ReflowGoal;
+use script_layout_interface::ReflowGoal;
 use selectors::attr::{AttrSelectorOperation, CaseSensitivity, NamespaceConstraint};
 use selectors::bloom::{BloomFilter, BLOOM_HASH_MASK};
 use selectors::matching::{ElementSelectorFlags, MatchingContext};
diff --git a/components/script/dom/htmlelement.rs b/components/script/dom/htmlelement.rs
index 9b84e9dbe29..3a7bd467215 100644
--- a/components/script/dom/htmlelement.rs
+++ b/components/script/dom/htmlelement.rs
@@ -9,7 +9,7 @@ use std::rc::Rc;
 use dom_struct::dom_struct;
 use html5ever::{local_name, namespace_url, ns, LocalName, Prefix};
 use js::rust::HandleObject;
-use script_layout_interface::message::QueryMsg;
+use script_layout_interface::QueryMsg;
 use style::attr::AttrValue;
 use style_traits::dom::ElementState;
 
diff --git a/components/script/dom/htmliframeelement.rs b/components/script/dom/htmliframeelement.rs
index 6d2cd80689a..cb84aa7bb52 100644
--- a/components/script/dom/htmliframeelement.rs
+++ b/components/script/dom/htmliframeelement.rs
@@ -10,7 +10,7 @@ use html5ever::{local_name, namespace_url, ns, LocalName, Prefix};
 use js::rust::HandleObject;
 use msg::constellation_msg::{BrowsingContextId, PipelineId, TopLevelBrowsingContextId};
 use profile_traits::ipc as ProfiledIpc;
-use script_layout_interface::message::ReflowGoal;
+use script_layout_interface::ReflowGoal;
 use script_traits::IFrameSandboxState::{IFrameSandboxed, IFrameUnsandboxed};
 use script_traits::{
     HistoryEntryReplacement, IFrameLoadInfo, IFrameLoadInfoWithData, JsEvalResult, LoadData,
diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
index 783c62204ce..2ddd18f9503 100644
--- a/components/script/dom/node.rs
+++ b/components/script/dom/node.rs
@@ -24,9 +24,8 @@ use libc::{self, c_void, uintptr_t};
 use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
 use msg::constellation_msg::{BrowsingContextId, PipelineId};
 use net_traits::image::base::{Image, ImageMetadata};
-use script_layout_interface::message::QueryMsg;
 use script_layout_interface::{
-    GenericLayoutData, HTMLCanvasData, HTMLMediaData, LayoutElementType, LayoutNodeType,
+    GenericLayoutData, HTMLCanvasData, HTMLMediaData, LayoutElementType, LayoutNodeType, QueryMsg,
     SVGSVGData, StyleData, TrustedNodeAddress,
 };
 use script_traits::{DocumentActivity, UntrustedNodeAddress};
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 268efc862ba..a8067c6d240 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -49,8 +49,9 @@ use parking_lot::Mutex as ParkMutex;
 use profile_traits::ipc as ProfiledIpc;
 use profile_traits::mem::ProfilerChan as MemProfilerChan;
 use profile_traits::time::ProfilerChan as TimeProfilerChan;
-use script_layout_interface::message::{Msg, QueryMsg, Reflow, ReflowGoal, ScriptReflow};
-use script_layout_interface::{Layout, PendingImageState, TrustedNodeAddress};
+use script_layout_interface::{
+    Layout, PendingImageState, QueryMsg, Reflow, ReflowGoal, ScriptReflow, TrustedNodeAddress,
+};
 use script_traits::webdriver_msg::{WebDriverJSError, WebDriverJSResult};
 use script_traits::{
     ConstellationControlMsg, DocumentState, HistoryEntryReplacement, LoadData, ScriptMsg,
@@ -1875,7 +1876,7 @@ impl Window {
             animations: document.animations().sets.clone(),
         };
 
-        let _ = self.with_layout(move |layout| layout.process(Msg::Reflow(reflow)));
+        let _ = self.with_layout(move |layout| layout.reflow(reflow));
 
         let complete = match join_port.try_recv() {
             Err(TryRecvError::Empty) => {
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index ccd867c1bb7..1991d30ae95 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -71,8 +71,9 @@ use parking_lot::Mutex;
 use percent_encoding::percent_decode;
 use profile_traits::mem::{self as profile_mem, OpaqueSender, ReportsChan};
 use profile_traits::time::{self as profile_time, profile, ProfilerCategory};
-use script_layout_interface::message::{Msg, ReflowGoal};
-use script_layout_interface::{Layout, LayoutConfig, LayoutFactory, ScriptThreadFactory};
+use script_layout_interface::{
+    Layout, LayoutConfig, LayoutFactory, ReflowGoal, ScriptThreadFactory,
+};
 use script_traits::webdriver_msg::WebDriverScriptCommand;
 use script_traits::CompositorEvent::{
     CompositionEvent, GamepadEvent, IMEDismissedEvent, KeyboardEvent, MouseButtonEvent,
@@ -1210,7 +1211,7 @@ impl ScriptThread {
         };
 
         let _ = window
-            .with_layout(|layout| layout.process(Msg::RegisterPaint(name, properties, painter)));
+            .with_layout(|layout| layout.register_paint_worklet_modules(name, properties, painter));
     }
 
     pub fn push_new_element_queue() {
@@ -2907,9 +2908,7 @@ impl ScriptThread {
             }
 
             debug!("{id}: Shutting down layout");
-            let _ = document.window().with_layout(|layout| {
-                layout.process(Msg::ExitNow);
-            });
+            let _ = document.window().with_layout(|layout| layout.exit_now());
 
             debug!("{id}: Sending PipelineExited message to constellation");
             self.script_sender
diff --git a/components/shared/msg/constellation_msg.rs b/components/shared/msg/constellation_msg.rs
index 6893957f46b..93c18790255 100644
--- a/components/shared/msg/constellation_msg.rs
+++ b/components/shared/msg/constellation_msg.rs
@@ -465,24 +465,6 @@ pub enum InputMethodType {
     Week,
 }
 
-#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
-/// The equivalent of script_layout_interface::message::Msg
-pub enum LayoutHangAnnotation {
-    AddStylesheet,
-    RemoveStylesheet,
-    SetQuirksMode,
-    Reflow,
-    CollectReports,
-    ExitNow,
-    GetCurrentEpoch,
-    GetWebFontLoadState,
-    CreateLayoutThread,
-    SetFinalUrl,
-    SetScrollStates,
-    UpdateScrollStateFromScript,
-    RegisterPaint,
-}
-
 #[derive(Clone, Copy, Debug, Deserialize, Serialize)]
 /// The equivalent of script::script_runtime::ScriptEventCategory
 pub enum ScriptHangAnnotation {
@@ -518,7 +500,6 @@ pub enum ScriptHangAnnotation {
 
 #[derive(Clone, Copy, Debug, Deserialize, Serialize)]
 pub enum HangAnnotation {
-    Layout(LayoutHangAnnotation),
     Script(ScriptHangAnnotation),
 }
 
diff --git a/components/shared/script_layout/lib.rs b/components/shared/script_layout/lib.rs
index b36c0c4ef56..e6d91ee86a0 100644
--- a/components/shared/script_layout/lib.rs
+++ b/components/shared/script_layout/lib.rs
@@ -8,7 +8,6 @@
 
 #![deny(unsafe_code)]
 
-pub mod message;
 pub mod wrapper_traits;
 
 use std::any::Any;
@@ -19,6 +18,7 @@ use std::sync::Arc;
 use app_units::Au;
 use atomic_refcell::AtomicRefCell;
 use canvas_traits::canvas::{CanvasId, CanvasMsg};
+use crossbeam_channel::Sender;
 use euclid::default::{Point2D, Rect};
 use euclid::Size2D;
 use gfx::font_cache_thread::FontCacheThread;
@@ -26,25 +26,28 @@ use gfx_traits::Epoch;
 use ipc_channel::ipc::IpcSender;
 use libc::c_void;
 use malloc_size_of_derive::MallocSizeOf;
-use message::NodesFromPointQueryType;
 use metrics::PaintTimeMetrics;
 use msg::constellation_msg::{BrowsingContextId, PipelineId};
 use net_traits::image_cache::{ImageCache, PendingImageId};
+use profile_traits::mem::ReportsChan;
 use profile_traits::time;
 use script_traits::{
-    ConstellationControlMsg, InitialScriptState, LayoutControlMsg, LayoutMsg, LoadData,
-    UntrustedNodeAddress, WebrenderIpcSender, WindowSizeData,
+    ConstellationControlMsg, InitialScriptState, LayoutControlMsg, LayoutMsg, LoadData, Painter,
+    ScrollState, UntrustedNodeAddress, WebrenderIpcSender, WindowSizeData,
 };
 use servo_arc::Arc as ServoArc;
 use servo_url::{ImmutableOrigin, ServoUrl};
 use style::animation::DocumentAnimationSet;
+use style::context::QuirksMode;
 use style::data::ElementData;
 use style::dom::OpaqueNode;
+use style::invalidation::element::restyle_hints::RestyleHint;
 use style::media_queries::Device;
 use style::properties::style_structs::Font;
 use style::properties::PropertyId;
-use style::selector_parser::PseudoElement;
+use style::selector_parser::{PseudoElement, RestyleDamage, Snapshot};
 use style::stylesheets::Stylesheet;
+use style::Atom;
 use style_traits::CSSPixel;
 use webrender_api::ImageKey;
 
@@ -171,9 +174,6 @@ pub trait LayoutFactory: Send + Sync {
 }
 
 pub trait Layout {
-    /// Process a single message from script.
-    fn process(&mut self, msg: message::Msg);
-
     /// Handle a single message from the Constellation.
     fn handle_constellation_msg(&mut self, msg: LayoutControlMsg);
 
@@ -203,9 +203,30 @@ pub trait Layout {
         before_stylsheet: Option<ServoArc<Stylesheet>>,
     );
 
+    /// Inform the layout that its ScriptThread is about to exit.
+    fn exit_now(&mut self);
+
+    /// Requests that layout measure its memory usage. The resulting reports are sent back
+    /// via the supplied channel.
+    fn collect_reports(&self, reports_chan: ReportsChan);
+
+    /// Sets quirks mode for the document, causing the quirks mode stylesheet to be used.
+    fn set_quirks_mode(&mut self, quirks_mode: QuirksMode);
+
     /// Removes a stylesheet from the Layout.
     fn remove_stylesheet(&mut self, stylesheet: ServoArc<Stylesheet>);
 
+    /// Requests a reflow.
+    fn reflow(&mut self, script_reflow: ScriptReflow);
+
+    /// Tells layout that script has added some paint worklet modules.
+    fn register_paint_worklet_modules(
+        &mut self,
+        name: Atom,
+        properties: Vec<Atom>,
+        painter: Box<dyn Painter>,
+    );
+
     fn query_content_box(&self, node: OpaqueNode) -> Option<Rect<Au>>;
     fn query_content_boxes(&self, node: OpaqueNode) -> Vec<Rect<Au>>;
     fn query_client_rect(&self, node: OpaqueNode) -> Rect<i32>;
@@ -257,3 +278,138 @@ pub struct OffsetParentResponse {
     pub node_address: Option<UntrustedNodeAddress>,
     pub rect: Rect<Au>,
 }
+
+#[derive(Debug, PartialEq)]
+pub enum NodesFromPointQueryType {
+    All,
+    Topmost,
+}
+
+#[derive(Debug, PartialEq)]
+pub enum QueryMsg {
+    ContentBox,
+    ContentBoxes,
+    ClientRectQuery,
+    ScrollingAreaQuery,
+    OffsetParentQuery,
+    TextIndexQuery,
+    NodesFromPointQuery,
+    ResolvedStyleQuery,
+    StyleQuery,
+    ElementInnerTextQuery,
+    ResolvedFontStyleQuery,
+    InnerWindowDimensionsQuery,
+}
+
+/// Any query to perform with this reflow.
+#[derive(Debug, PartialEq)]
+pub enum ReflowGoal {
+    Full,
+    TickAnimations,
+    LayoutQuery(QueryMsg, u64),
+
+    /// Tells layout about a single new scrolling offset from the script. The rest will
+    /// remain untouched and layout won't forward this back to script.
+    UpdateScrollNode(ScrollState),
+}
+
+impl ReflowGoal {
+    /// Returns true if the given ReflowQuery needs a full, up-to-date display list to
+    /// be present or false if it only needs stacking-relative positions.
+    pub fn needs_display_list(&self) -> bool {
+        match *self {
+            ReflowGoal::Full | ReflowGoal::TickAnimations | ReflowGoal::UpdateScrollNode(_) => true,
+            ReflowGoal::LayoutQuery(ref querymsg, _) => match *querymsg {
+                QueryMsg::ElementInnerTextQuery |
+                QueryMsg::InnerWindowDimensionsQuery |
+                QueryMsg::NodesFromPointQuery |
+                QueryMsg::ResolvedStyleQuery |
+                QueryMsg::TextIndexQuery => true,
+                QueryMsg::ClientRectQuery |
+                QueryMsg::ContentBox |
+                QueryMsg::ContentBoxes |
+                QueryMsg::OffsetParentQuery |
+                QueryMsg::ResolvedFontStyleQuery |
+                QueryMsg::ScrollingAreaQuery |
+                QueryMsg::StyleQuery => false,
+            },
+        }
+    }
+
+    /// Returns true if the given ReflowQuery needs its display list send to WebRender or
+    /// false if a layout_thread display list is sufficient.
+    pub fn needs_display(&self) -> bool {
+        match *self {
+            ReflowGoal::Full | ReflowGoal::TickAnimations | ReflowGoal::UpdateScrollNode(_) => true,
+            ReflowGoal::LayoutQuery(ref querymsg, _) => match *querymsg {
+                QueryMsg::NodesFromPointQuery |
+                QueryMsg::TextIndexQuery |
+                QueryMsg::ElementInnerTextQuery => true,
+                QueryMsg::ContentBox |
+                QueryMsg::ContentBoxes |
+                QueryMsg::ClientRectQuery |
+                QueryMsg::ScrollingAreaQuery |
+                QueryMsg::ResolvedStyleQuery |
+                QueryMsg::ResolvedFontStyleQuery |
+                QueryMsg::OffsetParentQuery |
+                QueryMsg::InnerWindowDimensionsQuery |
+                QueryMsg::StyleQuery => false,
+            },
+        }
+    }
+}
+
+/// Information needed for a reflow.
+pub struct Reflow {
+    ///  A clipping rectangle for the page, an enlarged rectangle containing the viewport.
+    pub page_clip_rect: Rect<Au>,
+}
+
+/// Information derived from a layout pass that needs to be returned to the script thread.
+#[derive(Default)]
+pub struct ReflowComplete {
+    /// The list of images that were encountered that are in progress.
+    pub pending_images: Vec<PendingImage>,
+}
+
+/// Information needed for a script-initiated reflow.
+pub struct ScriptReflow {
+    /// General reflow data.
+    pub reflow_info: Reflow,
+    /// The document node.
+    pub document: TrustedNodeAddress,
+    /// The dirty root from which to restyle.
+    pub dirty_root: Option<TrustedNodeAddress>,
+    /// Whether the document's stylesheets have changed since the last script reflow.
+    pub stylesheets_changed: bool,
+    /// The current window size.
+    pub window_size: WindowSizeData,
+    /// The channel that we send a notification to.
+    pub script_join_chan: Sender<ReflowComplete>,
+    /// The goal of this reflow.
+    pub reflow_goal: ReflowGoal,
+    /// The number of objects in the dom #10110
+    pub dom_count: u32,
+    /// The current window origin
+    pub origin: ImmutableOrigin,
+    /// Restyle snapshot map.
+    pub pending_restyles: Vec<(TrustedNodeAddress, PendingRestyle)>,
+    /// The current animation timeline value.
+    pub animation_timeline_value: f64,
+    /// The set of animations for this document.
+    pub animations: DocumentAnimationSet,
+}
+
+/// A pending restyle.
+#[derive(Debug, Default, MallocSizeOf)]
+pub struct PendingRestyle {
+    /// If this element had a state or attribute change since the last restyle, track
+    /// the original condition of the element.
+    pub snapshot: Option<Snapshot>,
+
+    /// Any explicit restyles hints that have been accumulated for this element.
+    pub hint: RestyleHint,
+
+    /// Any explicit restyles damage that have been accumulated for this element.
+    pub damage: RestyleDamage,
+}
diff --git a/components/shared/script_layout/message.rs b/components/shared/script_layout/message.rs
deleted file mode 100644
index 018e554e893..00000000000
--- a/components/shared/script_layout/message.rs
+++ /dev/null
@@ -1,188 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
-
-use app_units::Au;
-use crossbeam_channel::Sender;
-use euclid::default::Rect;
-use malloc_size_of_derive::MallocSizeOf;
-use profile_traits::mem::ReportsChan;
-use script_traits::{Painter, ScrollState, WindowSizeData};
-use servo_atoms::Atom;
-use servo_url::ImmutableOrigin;
-use style::animation::DocumentAnimationSet;
-use style::context::QuirksMode;
-use style::invalidation::element::restyle_hints::RestyleHint;
-use style::selector_parser::{RestyleDamage, Snapshot};
-
-use crate::{PendingImage, TrustedNodeAddress};
-
-/// Asynchronous messages that script can send to layout.
-pub enum Msg {
-    /// Change the quirks mode.
-    SetQuirksMode(QuirksMode),
-
-    /// Requests a reflow.
-    Reflow(ScriptReflow),
-
-    /// Requests that layout measure its memory usage. The resulting reports are sent back
-    /// via the supplied channel.
-    CollectReports(ReportsChan),
-
-    /// Requests that layout immediately shut down. There must be no more nodes left after
-    /// this, or layout will crash.
-    ExitNow,
-
-    /// Tells layout about the new scrolling offsets of each scrollable stacking context.
-    SetScrollStates(Vec<ScrollState>),
-
-    /// Tells layout that script has added some paint worklet modules.
-    RegisterPaint(Atom, Vec<Atom>, Box<dyn Painter>),
-}
-
-#[derive(Debug, PartialEq)]
-pub enum NodesFromPointQueryType {
-    All,
-    Topmost,
-}
-
-#[derive(Debug, PartialEq)]
-pub enum QueryMsg {
-    ContentBox,
-    ContentBoxes,
-    ClientRectQuery,
-    ScrollingAreaQuery,
-    OffsetParentQuery,
-    TextIndexQuery,
-    NodesFromPointQuery,
-    ResolvedStyleQuery,
-    StyleQuery,
-    ElementInnerTextQuery,
-    ResolvedFontStyleQuery,
-    InnerWindowDimensionsQuery,
-}
-
-/// Any query to perform with this reflow.
-#[derive(Debug, PartialEq)]
-pub enum ReflowGoal {
-    Full,
-    TickAnimations,
-    LayoutQuery(QueryMsg, u64),
-
-    /// Tells layout about a single new scrolling offset from the script. The rest will
-    /// remain untouched and layout won't forward this back to script.
-    UpdateScrollNode(ScrollState),
-}
-
-impl ReflowGoal {
-    /// Returns true if the given ReflowQuery needs a full, up-to-date display list to
-    /// be present or false if it only needs stacking-relative positions.
-    pub fn needs_display_list(&self) -> bool {
-        match *self {
-            ReflowGoal::Full | ReflowGoal::TickAnimations | ReflowGoal::UpdateScrollNode(_) => true,
-            ReflowGoal::LayoutQuery(ref querymsg, _) => match *querymsg {
-                QueryMsg::ElementInnerTextQuery |
-                QueryMsg::InnerWindowDimensionsQuery |
-                QueryMsg::NodesFromPointQuery |
-                QueryMsg::ResolvedStyleQuery |
-                QueryMsg::TextIndexQuery => true,
-                QueryMsg::ClientRectQuery |
-                QueryMsg::ContentBox |
-                QueryMsg::ContentBoxes |
-                QueryMsg::OffsetParentQuery |
-                QueryMsg::ResolvedFontStyleQuery |
-                QueryMsg::ScrollingAreaQuery |
-                QueryMsg::StyleQuery => false,
-            },
-        }
-    }
-
-    /// Returns true if the given ReflowQuery needs its display list send to WebRender or
-    /// false if a layout_thread display list is sufficient.
-    pub fn needs_display(&self) -> bool {
-        match *self {
-            ReflowGoal::Full | ReflowGoal::TickAnimations | ReflowGoal::UpdateScrollNode(_) => true,
-            ReflowGoal::LayoutQuery(ref querymsg, _) => match *querymsg {
-                QueryMsg::NodesFromPointQuery |
-                QueryMsg::TextIndexQuery |
-                QueryMsg::ElementInnerTextQuery => true,
-                QueryMsg::ContentBox |
-                QueryMsg::ContentBoxes |
-                QueryMsg::ClientRectQuery |
-                QueryMsg::ScrollingAreaQuery |
-                QueryMsg::ResolvedStyleQuery |
-                QueryMsg::ResolvedFontStyleQuery |
-                QueryMsg::OffsetParentQuery |
-                QueryMsg::InnerWindowDimensionsQuery |
-                QueryMsg::StyleQuery => false,
-            },
-        }
-    }
-}
-
-/// Information needed for a reflow.
-pub struct Reflow {
-    ///  A clipping rectangle for the page, an enlarged rectangle containing the viewport.
-    pub page_clip_rect: Rect<Au>,
-}
-
-/// Information derived from a layout pass that needs to be returned to the script thread.
-#[derive(Default)]
-pub struct ReflowComplete {
-    /// The list of images that were encountered that are in progress.
-    pub pending_images: Vec<PendingImage>,
-}
-
-/// Information needed for a script-initiated reflow.
-pub struct ScriptReflow {
-    /// General reflow data.
-    pub reflow_info: Reflow,
-    /// The document node.
-    pub document: TrustedNodeAddress,
-    /// The dirty root from which to restyle.
-    pub dirty_root: Option<TrustedNodeAddress>,
-    /// Whether the document's stylesheets have changed since the last script reflow.
-    pub stylesheets_changed: bool,
-    /// The current window size.
-    pub window_size: WindowSizeData,
-    /// The channel that we send a notification to.
-    pub script_join_chan: Sender<ReflowComplete>,
-    /// The goal of this reflow.
-    pub reflow_goal: ReflowGoal,
-    /// The number of objects in the dom #10110
-    pub dom_count: u32,
-    /// The current window origin
-    pub origin: ImmutableOrigin,
-    /// Restyle snapshot map.
-    pub pending_restyles: Vec<(TrustedNodeAddress, PendingRestyle)>,
-    /// The current animation timeline value.
-    pub animation_timeline_value: f64,
-    /// The set of animations for this document.
-    pub animations: DocumentAnimationSet,
-}
-
-/// A pending restyle.
-#[derive(Debug, MallocSizeOf)]
-pub struct PendingRestyle {
-    /// If this element had a state or attribute change since the last restyle, track
-    /// the original condition of the element.
-    pub snapshot: Option<Snapshot>,
-
-    /// Any explicit restyles hints that have been accumulated for this element.
-    pub hint: RestyleHint,
-
-    /// Any explicit restyles damage that have been accumulated for this element.
-    pub damage: RestyleDamage,
-}
-
-impl Default for PendingRestyle {
-    /// Creates a new empty pending restyle.
-    #[inline]
-    fn default() -> Self {
-        Self {
-            snapshot: None,
-            hint: RestyleHint::empty(),
-            damage: RestyleDamage::empty(),
-        }
-    }
-}