Auto merge of #26105 - servo:layout-2020-less-opaque, r=emilio

Make DOM own the style and layout data, in an UnsafeCell

21 files changed, 184 insertions, 247 deletions

diff --git a/components/layout/data.rs b/components/layout/data.rs
index 5f6672d1488..b965bc44ebd 100644
--- a/components/layout/data.rs
+++ b/components/layout/data.rs
@@ -8,8 +8,7 @@ use script_layout_interface::StyleData;
 
 #[repr(C)]
 pub struct StyleAndLayoutData {
-    /// Data accessed by script_layout_interface. This must be first to allow
-    /// casting between StyleAndLayoutData and StyleData.
+    /// The style data associated with a node.
     pub style_data: StyleData,
     /// The layout data associated with a node.
     pub layout_data: AtomicRefCell<LayoutData>,
diff --git a/components/layout/query.rs b/components/layout/query.rs
index cd3e75bf28c..b1e33a1dedf 100644
--- a/components/layout/query.rs
+++ b/components/layout/query.rs
@@ -6,6 +6,7 @@
 
 use crate::construct::ConstructionResult;
 use crate::context::LayoutContext;
+use crate::data::StyleAndLayoutData;
 use crate::display_list::items::{DisplayList, OpaqueNode, ScrollOffsetMap};
 use crate::display_list::IndexableText;
 use crate::flow::{Flow, GetBaseFlow};
@@ -26,7 +27,6 @@ use script_layout_interface::rpc::{OffsetParentResponse, ResolvedStyleResponse,
 use script_layout_interface::wrapper_traits::{
     LayoutNode, ThreadSafeLayoutElement, ThreadSafeLayoutNode,
 };
-use script_layout_interface::StyleData;
 use script_layout_interface::{LayoutElementType, LayoutNodeType};
 use script_traits::LayoutMsg as ConstellationMsg;
 use script_traits::UntrustedNodeAddress;
@@ -761,7 +761,7 @@ pub fn process_resolved_style_request<'dom>(
 
     // We call process_resolved_style_request after performing a whole-document
     // traversal, so in the common case, the element is styled.
-    if element.get_data().is_some() {
+    if element.has_data() {
         return process_resolved_style_request_internal(node, pseudo, property, layout_root);
     }
 
@@ -1036,9 +1036,14 @@ fn inner_text_collection_steps<'dom>(
             _ => child,
         };
 
-        let element_data = unsafe {
-            node.get_style_and_layout_data()
-                .map(|d| &(*(d.ptr.as_ptr() as *mut StyleData)).element_data)
+        let element_data = {
+            &node.get_style_and_layout_data().as_ref().map(|opaque| {
+                &opaque
+                    .downcast_ref::<StyleAndLayoutData>()
+                    .unwrap()
+                    .style_data
+                    .element_data
+            })
         };
 
         if element_data.is_none() {
diff --git a/components/layout/wrapper.rs b/components/layout/wrapper.rs
index 60eace1f16a..04648ad3abf 100644
--- a/components/layout/wrapper.rs
+++ b/components/layout/wrapper.rs
@@ -39,23 +39,21 @@ use style::selector_parser::RestyleDamage;
 use style::values::computed::counters::ContentItem;
 use style::values::generics::counters::Content;
 
-pub trait LayoutNodeLayoutData {
-    /// Similar to borrow_data*, but returns the full PersistentLayoutData rather
-    /// than only the style::data::ElementData.
-    fn borrow_layout_data(&self) -> Option<AtomicRef<LayoutData>>;
-    fn mutate_layout_data(&self) -> Option<AtomicRefMut<LayoutData>>;
+pub trait LayoutNodeLayoutData<'dom> {
+    fn borrow_layout_data(self) -> Option<AtomicRef<'dom, LayoutData>>;
+    fn mutate_layout_data(self) -> Option<AtomicRefMut<'dom, LayoutData>>;
     fn flow_debug_id(self) -> usize;
 }
 
-impl<'dom, T> LayoutNodeLayoutData for T
+impl<'dom, T> LayoutNodeLayoutData<'dom> for T
 where
     T: GetLayoutData<'dom>,
 {
-    fn borrow_layout_data(&self) -> Option<AtomicRef<LayoutData>> {
+    fn borrow_layout_data(self) -> Option<AtomicRef<'dom, LayoutData>> {
         self.get_raw_data().map(|d| d.layout_data.borrow())
     }
 
-    fn mutate_layout_data(&self) -> Option<AtomicRefMut<LayoutData>> {
+    fn mutate_layout_data(self) -> Option<AtomicRefMut<'dom, LayoutData>> {
         self.get_raw_data().map(|d| d.layout_data.borrow_mut())
     }
 
@@ -65,19 +63,17 @@ where
     }
 }
 
-pub trait GetRawData {
-    fn get_raw_data(&self) -> Option<&StyleAndLayoutData>;
+pub trait GetRawData<'dom> {
+    fn get_raw_data(self) -> Option<&'dom StyleAndLayoutData>;
 }
 
-impl<'dom, T> GetRawData for T
+impl<'dom, T> GetRawData<'dom> for T
 where
     T: GetLayoutData<'dom>,
 {
-    fn get_raw_data(&self) -> Option<&StyleAndLayoutData> {
-        self.get_style_and_layout_data().map(|opaque| {
-            let container = opaque.ptr.as_ptr() as *mut StyleAndLayoutData;
-            unsafe { &*container }
-        })
+    fn get_raw_data(self) -> Option<&'dom StyleAndLayoutData> {
+        self.get_style_and_layout_data()
+            .map(|opaque| opaque.downcast_ref().unwrap())
     }
 }
 
diff --git a/components/layout_2020/dom_traversal.rs b/components/layout_2020/dom_traversal.rs
index ef4570a85bb..8ea6bb01de7 100644
--- a/components/layout_2020/dom_traversal.rs
+++ b/components/layout_2020/dom_traversal.rs
@@ -369,7 +369,7 @@ pub(crate) trait NodeExt<'dom>: 'dom + Copy + LayoutNode<'dom> + Send + Sync {
     fn style(self, context: &LayoutContext) -> ServoArc<ComputedValues>;
 
     fn as_opaque(self) -> OpaqueNode;
-    fn layout_data_mut(&self) -> AtomicRefMut<LayoutDataForElement>;
+    fn layout_data_mut(self) -> AtomicRefMut<'dom, LayoutDataForElement>;
     fn element_box_slot(&self) -> BoxSlot<'dom>;
     fn pseudo_element_box_slot(&self, which: WhichPseudoElement) -> BoxSlot<'dom>;
     fn unset_pseudo_element_box(self, which: WhichPseudoElement);
@@ -446,7 +446,8 @@ where
         self.opaque()
     }
 
-    fn layout_data_mut(&self) -> AtomicRefMut<LayoutDataForElement> {
+    #[allow(unsafe_code)]
+    fn layout_data_mut(self) -> AtomicRefMut<'dom, LayoutDataForElement> {
         self.get_raw_data()
             .map(|d| d.layout_data.borrow_mut())
             .unwrap()
diff --git a/components/layout_2020/wrapper.rs b/components/layout_2020/wrapper.rs
index 504ab9af2cc..e7c5ab5a7b1 100644
--- a/components/layout_2020/wrapper.rs
+++ b/components/layout_2020/wrapper.rs
@@ -7,18 +7,16 @@
 use crate::data::StyleAndLayoutData;
 use script_layout_interface::wrapper_traits::GetLayoutData;
 
-pub trait GetRawData {
-    fn get_raw_data(&self) -> Option<&StyleAndLayoutData>;
+pub trait GetRawData<'dom> {
+    fn get_raw_data(self) -> Option<&'dom StyleAndLayoutData>;
 }
 
-impl<'dom, T> GetRawData for T
+impl<'dom, T> GetRawData<'dom> for T
 where
     T: GetLayoutData<'dom>,
 {
-    fn get_raw_data(&self) -> Option<&StyleAndLayoutData> {
-        self.get_style_and_layout_data().map(|opaque| {
-            let container = opaque.ptr.as_ptr() as *mut StyleAndLayoutData;
-            unsafe { &*container }
-        })
+    fn get_raw_data(self) -> Option<&'dom StyleAndLayoutData> {
+        self.get_style_and_layout_data()
+            .map(|opaque| opaque.downcast_ref().unwrap())
     }
 }
diff --git a/components/layout_thread/dom_wrapper.rs b/components/layout_thread/dom_wrapper.rs
index 9237e9d47e7..cbd0df1f9a4 100644
--- a/components/layout_thread/dom_wrapper.rs
+++ b/components/layout_thread/dom_wrapper.rs
@@ -30,7 +30,7 @@
 
 #![allow(unsafe_code)]
 
-use atomic_refcell::{AtomicRef, AtomicRefCell, AtomicRefMut};
+use atomic_refcell::{AtomicRef, AtomicRefMut};
 use gfx_traits::ByteIndex;
 use html5ever::{LocalName, Namespace};
 use layout::data::StyleAndLayoutData;
@@ -70,7 +70,6 @@ use std::borrow::Cow;
 use std::fmt;
 use std::fmt::Debug;
 use std::hash::{Hash, Hasher};
-use std::ptr::NonNull;
 use std::sync::atomic::Ordering;
 use std::sync::Arc as StdArc;
 use style::applicable_declarations::ApplicableDeclarationBlock;
@@ -92,12 +91,6 @@ use style::str::is_whitespace;
 use style::stylist::CascadeData;
 use style::CaseSensitivityExt;
 
-pub unsafe fn drop_style_and_layout_data(data: OpaqueStyleAndLayoutData) {
-    let ptr = data.ptr.as_ptr() as *mut StyleData;
-    let non_opaque: *mut StyleAndLayoutData = ptr as *mut _;
-    let _ = Box::from_raw(non_opaque);
-}
-
 #[derive(Clone, Copy)]
 pub struct ServoLayoutNode<'dom> {
     /// The wrapped node.
@@ -237,7 +230,7 @@ impl<'ln> TNode for ServoLayoutNode<'ln> {
     }
 
     fn opaque(&self) -> OpaqueNode {
-        unsafe { self.get_jsmanaged().opaque() }
+        self.get_jsmanaged().opaque()
     }
 
     fn debug_id(self) -> usize {
@@ -276,10 +269,7 @@ impl<'ln> LayoutNode<'ln> for ServoLayoutNode<'ln> {
 
     unsafe fn initialize_data(&self) {
         if self.get_raw_data().is_none() {
-            let ptr: *mut StyleAndLayoutData = Box::into_raw(Box::new(StyleAndLayoutData::new()));
-            let opaque = OpaqueStyleAndLayoutData {
-                ptr: NonNull::new_unchecked(ptr as *mut StyleData),
-            };
+            let opaque = OpaqueStyleAndLayoutData::new(StyleAndLayoutData::new());
             self.init_style_and_layout_data(opaque);
         };
     }
@@ -297,34 +287,33 @@ impl<'ln> LayoutNode<'ln> for ServoLayoutNode<'ln> {
     }
 }
 
-impl<'ln> GetLayoutData<'ln> for ServoLayoutNode<'ln> {
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
-        unsafe { self.get_jsmanaged().get_style_and_layout_data() }
+impl<'dom> GetLayoutData<'dom> for ServoLayoutNode<'dom> {
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData> {
+        self.get_jsmanaged().get_style_and_layout_data()
     }
 }
 
-impl<'le> GetLayoutData<'le> for ServoLayoutElement<'le> {
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
+impl<'dom> GetLayoutData<'dom> for ServoLayoutElement<'dom> {
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData> {
         self.as_node().get_style_and_layout_data()
     }
 }
 
-impl<'ln> GetLayoutData<'ln> for ServoThreadSafeLayoutNode<'ln> {
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
+impl<'dom> GetLayoutData<'dom> for ServoThreadSafeLayoutNode<'dom> {
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData> {
         self.node.get_style_and_layout_data()
     }
 }
 
-impl<'le> GetLayoutData<'le> for ServoThreadSafeLayoutElement<'le> {
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
+impl<'dom> GetLayoutData<'dom> for ServoThreadSafeLayoutElement<'dom> {
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData> {
         self.element.as_node().get_style_and_layout_data()
     }
 }
 
-impl<'ln> ServoLayoutNode<'ln> {
-    /// Returns the interior of this node as a `LayoutDom`. This is highly unsafe for layout to
-    /// call and as such is marked `unsafe`.
-    pub unsafe fn get_jsmanaged(&self) -> LayoutDom<'ln, Node> {
+impl<'dom> ServoLayoutNode<'dom> {
+    /// Returns the interior of this node as a `LayoutDom`.
+    pub fn get_jsmanaged(self) -> LayoutDom<'dom, Node> {
         self.node
     }
 }
@@ -548,7 +537,7 @@ impl<'le> TElement for ServoLayoutElement<'le> {
 
     unsafe fn clear_data(&self) {
         if self.get_raw_data().is_some() {
-            drop_style_and_layout_data(self.as_node().take_style_and_layout_data());
+            drop(self.as_node().take_style_and_layout_data());
         }
     }
 
@@ -557,11 +546,20 @@ impl<'le> TElement for ServoLayoutElement<'le> {
         self.mutate_data().unwrap()
     }
 
-    fn get_data(&self) -> Option<&AtomicRefCell<ElementData>> {
-        unsafe {
-            self.get_style_and_layout_data()
-                .map(|d| &(*(d.ptr.as_ptr() as *mut StyleData)).element_data)
-        }
+    /// Whether there is an ElementData container.
+    fn has_data(&self) -> bool {
+        self.get_style_data().is_some()
+    }
+
+    /// Immutably borrows the ElementData.
+    fn borrow_data(&self) -> Option<AtomicRef<ElementData>> {
+        self.get_style_data().map(|data| data.element_data.borrow())
+    }
+
+    /// Mutably borrows the ElementData.
+    fn mutate_data(&self) -> Option<AtomicRefMut<ElementData>> {
+        self.get_style_data()
+            .map(|data| data.element_data.borrow_mut())
     }
 
     fn skip_item_display_fixup(&self) -> bool {
@@ -697,10 +695,12 @@ impl<'le> ServoLayoutElement<'le> {
     }
 
     fn get_style_data(&self) -> Option<&StyleData> {
-        unsafe {
-            self.get_style_and_layout_data()
-                .map(|d| &*(d.ptr.as_ptr() as *mut StyleData))
-        }
+        self.get_style_and_layout_data().map(|opaque| {
+            &opaque
+                .downcast_ref::<StyleAndLayoutData>()
+                .unwrap()
+                .style_data
+        })
     }
 
     pub unsafe fn unset_snapshot_flags(&self) {
@@ -1034,7 +1034,7 @@ impl<'ln> ThreadSafeLayoutNode<'ln> for ServoThreadSafeLayoutNode<'ln> {
 
     fn parent_style(&self) -> Arc<ComputedValues> {
         let parent = self.node.parent_node().unwrap().as_element().unwrap();
-        let parent_data = parent.get_data().unwrap().borrow();
+        let parent_data = parent.borrow_data().unwrap();
         parent_data.styles.primary().clone()
     }
 
@@ -1060,7 +1060,7 @@ impl<'ln> ThreadSafeLayoutNode<'ln> for ServoThreadSafeLayoutNode<'ln> {
             })
     }
 
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
+    fn get_style_and_layout_data(self) -> Option<&'ln OpaqueStyleAndLayoutData> {
         self.node.get_style_and_layout_data()
     }
 
@@ -1319,10 +1319,7 @@ impl<'le> ThreadSafeLayoutElement<'le> for ServoThreadSafeLayoutElement<'le> {
     }
 
     fn style_data(&self) -> AtomicRef<ElementData> {
-        self.element
-            .get_data()
-            .expect("Unstyled layout node?")
-            .borrow()
+        self.element.borrow_data().expect("Unstyled layout node?")
     }
 
     fn is_shadow_host(&self) -> bool {
diff --git a/components/layout_thread/lib.rs b/components/layout_thread/lib.rs
index 54f1ec8d656..4c458065986 100644
--- a/components/layout_thread/lib.rs
+++ b/components/layout_thread/lib.rs
@@ -23,7 +23,6 @@ extern crate profile_traits;
 
 mod dom_wrapper;
 
-use crate::dom_wrapper::drop_style_and_layout_data;
 use crate::dom_wrapper::{ServoLayoutDocument, ServoLayoutElement, ServoLayoutNode};
 use app_units::Au;
 use crossbeam_channel::{unbounded, Receiver, Sender};
@@ -692,7 +691,6 @@ impl LayoutThread {
             Msg::GetRPC(..) => LayoutHangAnnotation::GetRPC,
             Msg::TickAnimations(..) => LayoutHangAnnotation::TickAnimations,
             Msg::AdvanceClockMs(..) => LayoutHangAnnotation::AdvanceClockMs,
-            Msg::ReapStyleAndLayoutData(..) => LayoutHangAnnotation::ReapStyleAndLayoutData,
             Msg::CollectReports(..) => LayoutHangAnnotation::CollectReports,
             Msg::PrepareToExit(..) => LayoutHangAnnotation::PrepareToExit,
             Msg::ExitNow => LayoutHangAnnotation::ExitNow,
@@ -833,9 +831,6 @@ impl LayoutThread {
                     webrender_api::ScrollClamping::ToContentBounds,
                 );
             },
-            Msg::ReapStyleAndLayoutData(dead_data) => unsafe {
-                drop_style_and_layout_data(dead_data)
-            },
             Msg::CollectReports(reports_chan) => {
                 self.collect_reports(reports_chan, possibly_locked_rw_data);
             },
@@ -967,9 +962,6 @@ impl LayoutThread {
         response_chan.send(()).unwrap();
         loop {
             match self.port.recv().unwrap() {
-                Msg::ReapStyleAndLayoutData(dead_data) => unsafe {
-                    drop_style_and_layout_data(dead_data)
-                },
                 Msg::ExitNow => {
                     debug!("layout thread is exiting...");
                     self.exit_now();
@@ -1472,7 +1464,7 @@ impl LayoutThread {
 
             // If we haven't styled this node yet, we don't need to track a
             // restyle.
-            let style_data = match el.get_data() {
+            let mut style_data = match el.mutate_data() {
                 Some(d) => d,
                 None => {
                     unsafe { el.unset_snapshot_flags() };
@@ -1485,8 +1477,6 @@ impl LayoutThread {
                 map.insert(el.as_node().opaque(), s);
             }
 
-            let mut style_data = style_data.borrow_mut();
-
             // Stash the data on the element for processing by the style system.
             style_data.hint.insert(restyle.hint.into());
             style_data.damage = restyle.damage;
diff --git a/components/layout_thread_2020/dom_wrapper.rs b/components/layout_thread_2020/dom_wrapper.rs
index 5a722cd82b8..b396eeee5cc 100644
--- a/components/layout_thread_2020/dom_wrapper.rs
+++ b/components/layout_thread_2020/dom_wrapper.rs
@@ -30,7 +30,7 @@
 
 #![allow(unsafe_code)]
 
-use atomic_refcell::{AtomicRef, AtomicRefCell, AtomicRefMut};
+use atomic_refcell::{AtomicRef, AtomicRefMut};
 use gfx_traits::ByteIndex;
 use html5ever::{LocalName, Namespace};
 use layout::data::StyleAndLayoutData;
@@ -70,7 +70,6 @@ use std::borrow::Cow;
 use std::fmt;
 use std::fmt::Debug;
 use std::hash::{Hash, Hasher};
-use std::ptr::NonNull;
 use std::sync::atomic::Ordering;
 use std::sync::Arc as StdArc;
 use style::applicable_declarations::ApplicableDeclarationBlock;
@@ -92,12 +91,6 @@ use style::str::is_whitespace;
 use style::stylist::CascadeData;
 use style::CaseSensitivityExt;
 
-pub unsafe fn drop_style_and_layout_data(data: OpaqueStyleAndLayoutData) {
-    let ptr = data.ptr.as_ptr() as *mut StyleData;
-    let non_opaque: *mut StyleAndLayoutData = ptr as *mut _;
-    let _ = Box::from_raw(non_opaque);
-}
-
 #[derive(Clone, Copy)]
 pub struct ServoLayoutNode<'dom> {
     /// The wrapped node.
@@ -283,10 +276,7 @@ impl<'ln> LayoutNode<'ln> for ServoLayoutNode<'ln> {
 
     unsafe fn initialize_data(&self) {
         if self.get_raw_data().is_none() {
-            let ptr: *mut StyleAndLayoutData = Box::into_raw(Box::new(StyleAndLayoutData::new()));
-            let opaque = OpaqueStyleAndLayoutData {
-                ptr: NonNull::new_unchecked(ptr as *mut StyleData),
-            };
+            let opaque = OpaqueStyleAndLayoutData::new(StyleAndLayoutData::new());
             self.init_style_and_layout_data(opaque);
         };
     }
@@ -304,26 +294,26 @@ impl<'ln> LayoutNode<'ln> for ServoLayoutNode<'ln> {
     }
 }
 
-impl<'ln> GetLayoutData<'ln> for ServoLayoutNode<'ln> {
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
+impl<'dom> GetLayoutData<'dom> for ServoLayoutNode<'dom> {
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData> {
         unsafe { self.get_jsmanaged().get_style_and_layout_data() }
     }
 }
 
-impl<'le> GetLayoutData<'le> for ServoLayoutElement<'le> {
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
+impl<'dom> GetLayoutData<'dom> for ServoLayoutElement<'dom> {
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData> {
         self.as_node().get_style_and_layout_data()
     }
 }
 
-impl<'ln> GetLayoutData<'ln> for ServoThreadSafeLayoutNode<'ln> {
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
+impl<'dom> GetLayoutData<'dom> for ServoThreadSafeLayoutNode<'dom> {
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData> {
         self.node.get_style_and_layout_data()
     }
 }
 
-impl<'le> GetLayoutData<'le> for ServoThreadSafeLayoutElement<'le> {
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
+impl<'dom> GetLayoutData<'dom> for ServoThreadSafeLayoutElement<'dom> {
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData> {
         self.element.as_node().get_style_and_layout_data()
     }
 }
@@ -555,7 +545,7 @@ impl<'le> TElement for ServoLayoutElement<'le> {
 
     unsafe fn clear_data(&self) {
         if self.get_raw_data().is_some() {
-            drop_style_and_layout_data(self.as_node().take_style_and_layout_data());
+            drop(self.as_node().take_style_and_layout_data());
         }
     }
 
@@ -564,11 +554,20 @@ impl<'le> TElement for ServoLayoutElement<'le> {
         self.mutate_data().unwrap()
     }
 
-    fn get_data(&self) -> Option<&AtomicRefCell<ElementData>> {
-        unsafe {
-            self.get_style_and_layout_data()
-                .map(|d| &(*(d.ptr.as_ptr() as *mut StyleData)).element_data)
-        }
+    /// Whether there is an ElementData container.
+    fn has_data(&self) -> bool {
+        self.get_style_data().is_some()
+    }
+
+    /// Immutably borrows the ElementData.
+    fn borrow_data(&self) -> Option<AtomicRef<ElementData>> {
+        self.get_style_data().map(|data| data.element_data.borrow())
+    }
+
+    /// Mutably borrows the ElementData.
+    fn mutate_data(&self) -> Option<AtomicRefMut<ElementData>> {
+        self.get_style_data()
+            .map(|data| data.element_data.borrow_mut())
     }
 
     fn skip_item_display_fixup(&self) -> bool {
@@ -704,10 +703,12 @@ impl<'le> ServoLayoutElement<'le> {
     }
 
     fn get_style_data(&self) -> Option<&StyleData> {
-        unsafe {
-            self.get_style_and_layout_data()
-                .map(|d| &*(d.ptr.as_ptr() as *mut StyleData))
-        }
+        self.get_style_and_layout_data().map(|opaque| {
+            &opaque
+                .downcast_ref::<StyleAndLayoutData>()
+                .unwrap()
+                .style_data
+        })
     }
 
     pub unsafe fn unset_snapshot_flags(&self) {
@@ -1041,7 +1042,7 @@ impl<'ln> ThreadSafeLayoutNode<'ln> for ServoThreadSafeLayoutNode<'ln> {
 
     fn parent_style(&self) -> Arc<ComputedValues> {
         let parent = self.node.parent_node().unwrap().as_element().unwrap();
-        let parent_data = parent.get_data().unwrap().borrow();
+        let parent_data = parent.borrow_data().unwrap();
         parent_data.styles.primary().clone()
     }
 
@@ -1067,7 +1068,7 @@ impl<'ln> ThreadSafeLayoutNode<'ln> for ServoThreadSafeLayoutNode<'ln> {
             })
     }
 
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData> {
+    fn get_style_and_layout_data(self) -> Option<&'ln OpaqueStyleAndLayoutData> {
         self.node.get_style_and_layout_data()
     }
 
@@ -1326,10 +1327,7 @@ impl<'le> ThreadSafeLayoutElement<'le> for ServoThreadSafeLayoutElement<'le> {
     }
 
     fn style_data(&self) -> AtomicRef<ElementData> {
-        self.element
-            .get_data()
-            .expect("Unstyled layout node?")
-            .borrow()
+        self.element.borrow_data().expect("Unstyled layout node?")
     }
 
     fn is_shadow_host(&self) -> bool {
diff --git a/components/layout_thread_2020/lib.rs b/components/layout_thread_2020/lib.rs
index 05663f7d68b..812a8823f38 100644
--- a/components/layout_thread_2020/lib.rs
+++ b/components/layout_thread_2020/lib.rs
@@ -21,7 +21,6 @@ extern crate profile_traits;
 
 mod dom_wrapper;
 
-use crate::dom_wrapper::drop_style_and_layout_data;
 use crate::dom_wrapper::{ServoLayoutDocument, ServoLayoutElement, ServoLayoutNode};
 use app_units::Au;
 use crossbeam_channel::{unbounded, Receiver, Sender};
@@ -640,7 +639,6 @@ impl LayoutThread {
             Msg::GetRPC(..) => LayoutHangAnnotation::GetRPC,
             Msg::TickAnimations(..) => LayoutHangAnnotation::TickAnimations,
             Msg::AdvanceClockMs(..) => LayoutHangAnnotation::AdvanceClockMs,
-            Msg::ReapStyleAndLayoutData(..) => LayoutHangAnnotation::ReapStyleAndLayoutData,
             Msg::CollectReports(..) => LayoutHangAnnotation::CollectReports,
             Msg::PrepareToExit(..) => LayoutHangAnnotation::PrepareToExit,
             Msg::ExitNow => LayoutHangAnnotation::ExitNow,
@@ -779,9 +777,6 @@ impl LayoutThread {
                     webrender_api::ScrollClamping::ToContentBounds,
                 );
             },
-            Msg::ReapStyleAndLayoutData(dead_data) => unsafe {
-                drop_style_and_layout_data(dead_data)
-            },
             Msg::CollectReports(reports_chan) => {
                 self.collect_reports(reports_chan, possibly_locked_rw_data);
             },
@@ -890,9 +885,6 @@ impl LayoutThread {
         response_chan.send(()).unwrap();
         loop {
             match self.port.recv().unwrap() {
-                Msg::ReapStyleAndLayoutData(dead_data) => unsafe {
-                    drop_style_and_layout_data(dead_data)
-                },
                 Msg::ExitNow => {
                     debug!("layout thread is exiting...");
                     self.exit_now();
@@ -1118,7 +1110,7 @@ impl LayoutThread {
 
             // If we haven't styled this node yet, we don't need to track a
             // restyle.
-            let style_data = match el.get_data() {
+            let mut style_data = match el.mutate_data() {
                 Some(d) => d,
                 None => {
                     unsafe { el.unset_snapshot_flags() };
@@ -1131,8 +1123,6 @@ impl LayoutThread {
                 map.insert(el.as_node().opaque(), s);
             }
 
-            let mut style_data = style_data.borrow_mut();
-
             // Stash the data on the element for processing by the style system.
             style_data.hint.insert(restyle.hint.into());
             style_data.damage = restyle.damage;
diff --git a/components/msg/constellation_msg.rs b/components/msg/constellation_msg.rs
index a878bc43d3d..ae0ceb39b18 100644
--- a/components/msg/constellation_msg.rs
+++ b/components/msg/constellation_msg.rs
@@ -532,7 +532,6 @@ pub enum LayoutHangAnnotation {
     GetRPC,
     TickAnimations,
     AdvanceClockMs,
-    ReapStyleAndLayoutData,
     CollectReports,
     PrepareToExit,
     ExitNow,
diff --git a/components/script/dom/node.rs b/components/script/dom/node.rs
index f9007bcf9c6..8530078c919 100644
--- a/components/script/dom/node.rs
+++ b/components/script/dom/node.rs
@@ -65,7 +65,6 @@ use crate::dom::virtualmethods::{vtable_for, VirtualMethods};
 use crate::dom::window::Window;
 use crate::script_thread::ScriptThread;
 use app_units::Au;
-use crossbeam_channel::Sender;
 use devtools_traits::NodeInfo;
 use dom_struct::dom_struct;
 use euclid::default::{Point2D, Rect, Size2D, Vector2D};
@@ -76,7 +75,6 @@ use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
 use msg::constellation_msg::{BrowsingContextId, PipelineId};
 use net_traits::image::base::{Image, ImageMetadata};
 use ref_slice::ref_slice;
-use script_layout_interface::message::Msg;
 use script_layout_interface::{HTMLCanvasData, HTMLMediaData, LayoutElementType, LayoutNodeType};
 use script_layout_interface::{OpaqueStyleAndLayoutData, SVGSVGData, TrustedNodeAddress};
 use script_traits::DocumentActivity;
@@ -99,7 +97,6 @@ use style::context::QuirksMode;
 use style::dom::OpaqueNode;
 use style::selector_parser::{SelectorImpl, SelectorParser};
 use style::stylesheets::Stylesheet;
-use style::thread_state;
 use uuid::Uuid;
 
 //
@@ -155,7 +152,8 @@ pub struct Node {
     ///
     /// Must be sent back to the layout thread to be destroyed when this
     /// node is finalized.
-    style_and_layout_data: Cell<Option<OpaqueStyleAndLayoutData>>,
+    #[ignore_malloc_size_of = "shrug"]
+    style_and_layout_data: UnsafeCell<Option<OpaqueStyleAndLayoutData>>,
 }
 
 bitflags! {
@@ -205,15 +203,6 @@ impl NodeFlags {
     }
 }
 
-impl Drop for Node {
-    #[allow(unsafe_code)]
-    fn drop(&mut self) {
-        if let Some(data) = self.style_and_layout_data.get() {
-            self.dispose(data, ScriptThread::get_any_layout_chan().as_ref());
-        }
-    }
-}
-
 /// suppress observers flag
 /// <https://dom.spec.whatwg.org/#concept-node-insert>
 /// <https://dom.spec.whatwg.org/#concept-node-remove>
@@ -224,21 +213,6 @@ enum SuppressObserver {
 }
 
 impl Node {
-    /// Sends the style and layout data, if any, back to the layout thread to be destroyed.
-    pub(crate) fn dispose(
-        &self,
-        data: OpaqueStyleAndLayoutData,
-        layout_chan: Option<&Sender<Msg>>,
-    ) {
-        debug_assert!(thread_state::get().is_script());
-        self.style_and_layout_data.set(None);
-        if layout_chan.map_or(false, |chan| {
-            chan.send(Msg::ReapStyleAndLayoutData(data)).is_err()
-        }) {
-            warn!("layout thread unreachable - leaking layout data");
-        }
-    }
-
     /// Adds a new child to the end of this node's list of children.
     ///
     /// Fails unless `new_child` is disconnected from the tree.
@@ -317,16 +291,11 @@ impl Node {
                 false,
             );
         }
-        let window = window_from_node(root);
-        let layout_chan = window.layout_chan();
         for node in root.traverse_preorder(ShadowIncluding::Yes) {
             // This needs to be in its own loop, because unbind_from_tree may
             // rely on the state of IS_IN_DOC of the context node's descendants,
             // e.g. when removing a <form>.
             vtable_for(&&*node).unbind_from_tree(&context);
-            if let Some(data) = node.style_and_layout_data.get() {
-                node.dispose(data, Some(layout_chan));
-            }
             // https://dom.spec.whatwg.org/#concept-node-remove step 14
             if let Some(element) = node.as_custom_element() {
                 ScriptThread::enqueue_callback_reaction(
@@ -507,15 +476,6 @@ impl<'a> Iterator for QuerySelectorIterator {
 impl Node {
     impl_rare_data!(NodeRareData);
 
-    pub(crate) fn teardown(&self, layout_chan: &Sender<Msg>) {
-        if let Some(data) = self.style_and_layout_data.get() {
-            self.dispose(data, Some(layout_chan));
-        }
-        for kid in self.children() {
-            kid.teardown(layout_chan);
-        }
-    }
-
     /// Returns true if this node is before `other` in the same connected DOM
     /// tree.
     pub fn is_before(&self, other: &Node) -> bool {
@@ -1322,8 +1282,8 @@ pub trait LayoutNodeHelpers<'dom> {
 
     fn children_count(self) -> u32;
 
-    unsafe fn get_style_and_layout_data(self) -> Option<OpaqueStyleAndLayoutData>;
-    unsafe fn init_style_and_layout_data(self, _: OpaqueStyleAndLayoutData);
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData>;
+    unsafe fn init_style_and_layout_data(self, data: OpaqueStyleAndLayoutData);
     unsafe fn take_style_and_layout_data(self) -> OpaqueStyleAndLayoutData;
 
     fn text_content(self) -> Cow<'dom, str>;
@@ -1450,23 +1410,24 @@ impl<'dom> LayoutNodeHelpers<'dom> for LayoutDom<'dom, Node> {
 
     #[inline]
     #[allow(unsafe_code)]
-    unsafe fn get_style_and_layout_data(self) -> Option<OpaqueStyleAndLayoutData> {
-        (*self.unsafe_get()).style_and_layout_data.get()
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData> {
+        unsafe { (*self.unsafe_get().style_and_layout_data.get()).as_ref() }
     }
 
     #[inline]
     #[allow(unsafe_code)]
     unsafe fn init_style_and_layout_data(self, val: OpaqueStyleAndLayoutData) {
-        debug_assert!((*self.unsafe_get()).style_and_layout_data.get().is_none());
-        (*self.unsafe_get()).style_and_layout_data.set(Some(val));
+        let data = &mut *self.unsafe_get().style_and_layout_data.get();
+        debug_assert!(data.is_none());
+        *data = Some(val);
     }
 
     #[inline]
     #[allow(unsafe_code)]
     unsafe fn take_style_and_layout_data(self) -> OpaqueStyleAndLayoutData {
-        let val = (*self.unsafe_get()).style_and_layout_data.get().unwrap();
-        (*self.unsafe_get()).style_and_layout_data.set(None);
-        val
+        (*self.unsafe_get().style_and_layout_data.get())
+            .take()
+            .unwrap()
     }
 
     fn text_content(self) -> Cow<'dom, str> {
@@ -1781,7 +1742,7 @@ impl Node {
             inclusive_descendants_version: Cell::new(0),
             ranges: WeakRangeVec::new(),
 
-            style_and_layout_data: Cell::new(None),
+            style_and_layout_data: UnsafeCell::new(None),
         }
     }
 
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index 36916f3ef51..6782047c5a2 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -1399,13 +1399,6 @@ impl Window {
     }
 
     pub fn clear_js_runtime(&self) {
-        // We tear down the active document, which causes all the attached
-        // nodes to dispose of their layout data. This messages the layout
-        // thread, informing it that it can safely free the memory.
-        self.Document()
-            .upcast::<Node>()
-            .teardown(self.layout_chan());
-
         // Remove the infra for managing messageports and broadcast channels.
         self.upcast::<GlobalScope>().remove_web_messaging_infra();
 
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index 714c6857d9c..d6a8481afb3 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -822,23 +822,6 @@ impl ScriptThreadFactory for ScriptThread {
 }
 
 impl ScriptThread {
-    pub(crate) fn get_any_layout_chan() -> Option<Sender<Msg>> {
-        SCRIPT_THREAD_ROOT.with(|root| {
-            let script_thread = match root.get() {
-                Some(s) => unsafe { &*s },
-                None => return None,
-            };
-            script_thread
-                .documents
-                .borrow()
-                .map
-                .values()
-                .next()
-                .map(|d| d.window().layout_chan())
-                .cloned()
-        })
-    }
-
     pub fn runtime_handle() -> ParentRuntime {
         SCRIPT_THREAD_ROOT.with(|root| {
             let script_thread = unsafe { &*root.get().unwrap() };
diff --git a/components/script_layout_interface/lib.rs b/components/script_layout_interface/lib.rs
index ef9382378cb..6fb859aa112 100644
--- a/components/script_layout_interface/lib.rs
+++ b/components/script_layout_interface/lib.rs
@@ -7,6 +7,7 @@
 //! to depend on script.
 
 #![deny(unsafe_code)]
+#![feature(box_into_raw_non_null)]
 
 #[macro_use]
 extern crate html5ever;
@@ -24,7 +25,7 @@ use libc::c_void;
 use net_traits::image_cache::PendingImageId;
 use script_traits::UntrustedNodeAddress;
 use servo_url::{ImmutableOrigin, ServoUrl};
-use std::ptr::NonNull;
+use std::any::Any;
 use std::sync::atomic::AtomicIsize;
 use style::data::ElementData;
 
@@ -49,12 +50,32 @@ impl StyleData {
     }
 }
 
-#[derive(Clone, Copy, MallocSizeOf)]
+#[derive(MallocSizeOf)]
 pub struct OpaqueStyleAndLayoutData {
     // NB: We really store a `StyleAndLayoutData` here, so be careful!
-    #[ignore_malloc_size_of = "TODO(#6910) Box value that should be counted but \
-                               the type lives in layout"]
-    pub ptr: NonNull<StyleData>,
+    #[ignore_malloc_size_of = "Trait objects are hard"]
+    ptr: Box<dyn Any + Send + Sync>,
+}
+
+impl OpaqueStyleAndLayoutData {
+    #[inline]
+    pub fn new<T>(value: T) -> Self
+    where
+        T: Any + Send + Sync,
+    {
+        Self {
+            ptr: Box::new(value) as Box<dyn Any + Send + Sync>,
+        }
+    }
+
+    /// Extremely cursed.
+    #[inline]
+    pub fn downcast_ref<T>(&self) -> Option<&T>
+    where
+        T: Any + Send + Sync,
+    {
+        self.ptr.downcast_ref()
+    }
 }
 
 #[allow(unsafe_code)]
diff --git a/components/script_layout_interface/message.rs b/components/script_layout_interface/message.rs
index 96c4a132368..48ec7223250 100644
--- a/components/script_layout_interface/message.rs
+++ b/components/script_layout_interface/message.rs
@@ -3,7 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use crate::rpc::LayoutRPC;
-use crate::{OpaqueStyleAndLayoutData, PendingImage, TrustedNodeAddress};
+use crate::{PendingImage, TrustedNodeAddress};
 use app_units::Au;
 use crossbeam_channel::{Receiver, Sender};
 use euclid::default::{Point2D, Rect};
@@ -56,11 +56,6 @@ pub enum Msg {
     /// field is whether animations should be force-ticked.
     AdvanceClockMs(i32, bool, ImmutableOrigin),
 
-    /// Destroys layout data associated with a DOM node.
-    ///
-    /// TODO(pcwalton): Maybe think about batching to avoid message traffic.
-    ReapStyleAndLayoutData(OpaqueStyleAndLayoutData),
-
     /// Requests that the layout thread measure its memory usage. The resulting reports are sent back
     /// via the supplied channel.
     CollectReports(ReportsChan),
diff --git a/components/script_layout_interface/wrapper_traits.rs b/components/script_layout_interface/wrapper_traits.rs
index 462d11f2c7e..671dd1c8230 100644
--- a/components/script_layout_interface/wrapper_traits.rs
+++ b/components/script_layout_interface/wrapper_traits.rs
@@ -80,7 +80,7 @@ impl PseudoElementType {
 
 /// Trait to abstract access to layout data across various data structures.
 pub trait GetLayoutData<'dom> {
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData>;
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData>;
 }
 
 /// A wrapper so that layout can access only the methods that it should have access to. Layout must
@@ -224,7 +224,7 @@ pub trait ThreadSafeLayoutNode<'dom>:
             .map_or(PseudoElementType::Normal, |el| el.get_pseudo_element_type())
     }
 
-    fn get_style_and_layout_data(&self) -> Option<OpaqueStyleAndLayoutData>;
+    fn get_style_and_layout_data(self) -> Option<&'dom OpaqueStyleAndLayoutData>;
 
     fn style(&self, context: &SharedStyleContext) -> Arc<ComputedValues> {
         if let Some(el) = self.as_element() {
diff --git a/components/style/dom.rs b/components/style/dom.rs
index 7629bb11e18..d07cac998ae 100644
--- a/components/style/dom.rs
+++ b/components/style/dom.rs
@@ -22,7 +22,7 @@ use crate::shared_lock::Locked;
 use crate::stylist::CascadeData;
 use crate::traversal_flags::TraversalFlags;
 use crate::{Atom, LocalName, Namespace, WeakAtom};
-use atomic_refcell::{AtomicRef, AtomicRefCell, AtomicRefMut};
+use atomic_refcell::{AtomicRef, AtomicRefMut};
 use selectors::matching::{ElementSelectorFlags, QuirksMode, VisitedHandlingMode};
 use selectors::sink::Push;
 use selectors::Element as SelectorsElement;
@@ -689,18 +689,14 @@ pub trait TElement:
     /// Unsafe following the same reasoning as ensure_data.
     unsafe fn clear_data(&self);
 
-    /// Gets a reference to the ElementData container.
-    fn get_data(&self) -> Option<&AtomicRefCell<ElementData>>;
+    /// Whether there is an ElementData container.
+    fn has_data(&self) -> bool;
 
     /// Immutably borrows the ElementData.
-    fn borrow_data(&self) -> Option<AtomicRef<ElementData>> {
-        self.get_data().map(|x| x.borrow())
-    }
+    fn borrow_data(&self) -> Option<AtomicRef<ElementData>>;
 
     /// Mutably borrows the ElementData.
-    fn mutate_data(&self) -> Option<AtomicRefMut<ElementData>> {
-        self.get_data().map(|x| x.borrow_mut())
-    }
+    fn mutate_data(&self) -> Option<AtomicRefMut<ElementData>>;
 
     /// Whether we should skip any root- or item-based display property
     /// blockification on this element.  (This function exists so that Gecko
diff --git a/components/style/gecko/wrapper.rs b/components/style/gecko/wrapper.rs
index ba1c724d58f..2b842e72d9b 100644
--- a/components/style/gecko/wrapper.rs
+++ b/components/style/gecko/wrapper.rs
@@ -558,6 +558,11 @@ impl<'le> fmt::Debug for GeckoElement<'le> {
 
 impl<'le> GeckoElement<'le> {
     #[inline(always)]
+    fn get_data(&self) -> Option<&AtomicRefCell<ElementData>> {
+        unsafe { self.0.mServoData.get().as_ref() }
+    }
+
+    #[inline(always)]
     fn attrs(&self) -> &[structs::AttrArray_InternalAttr] {
         unsafe {
             let attrs = match self.0.mAttrs.mImpl.mPtr.as_ref() {
@@ -1299,7 +1304,7 @@ impl<'le> TElement for GeckoElement<'le> {
     }
 
     unsafe fn set_handled_snapshot(&self) {
-        debug_assert!(self.get_data().is_some());
+        debug_assert!(self.has_data());
         self.set_flags(ELEMENT_HANDLED_SNAPSHOT as u32)
     }
 
@@ -1309,7 +1314,7 @@ impl<'le> TElement for GeckoElement<'le> {
     }
 
     unsafe fn set_dirty_descendants(&self) {
-        debug_assert!(self.get_data().is_some());
+        debug_assert!(self.has_data());
         debug!("Setting dirty descendants: {:?}", self);
         self.set_flags(ELEMENT_HAS_DIRTY_DESCENDANTS_FOR_SERVO as u32)
     }
@@ -1378,13 +1383,23 @@ impl<'le> TElement for GeckoElement<'le> {
         panic!("Atomic child count not implemented in Gecko");
     }
 
-    #[inline(always)]
-    fn get_data(&self) -> Option<&AtomicRefCell<ElementData>> {
-        unsafe { self.0.mServoData.get().as_ref() }
+    /// Whether there is an ElementData container.
+    fn has_data(&self) -> bool {
+        self.get_data().is_some()
+    }
+
+    /// Immutably borrows the ElementData.
+    fn borrow_data(&self) -> Option<AtomicRef<ElementData>> {
+        self.get_data().map(|x| x.borrow())
+    }
+
+    /// Mutably borrows the ElementData.
+    fn mutate_data(&self) -> Option<AtomicRefMut<ElementData>> {
+        self.get_data().map(|x| x.borrow_mut())
     }
 
     unsafe fn ensure_data(&self) -> AtomicRefMut<ElementData> {
-        if self.get_data().is_none() {
+        if !self.has_data() {
             debug!("Creating ElementData for {:?}", self);
             let ptr = Box::into_raw(Box::new(AtomicRefCell::new(ElementData::default())));
             self.0.mServoData.set(ptr);
diff --git a/components/style/invalidation/element/state_and_attributes.rs b/components/style/invalidation/element/state_and_attributes.rs
index 628f174a3d7..e906f8d8405 100644
--- a/components/style/invalidation/element/state_and_attributes.rs
+++ b/components/style/invalidation/element/state_and_attributes.rs
@@ -90,7 +90,7 @@ pub fn invalidated_descendants<E>(element: E, child: E)
 where
     E: TElement,
 {
-    if child.get_data().is_none() {
+    if !child.has_data() {
         return;
     }
 
diff --git a/components/style/traversal.rs b/components/style/traversal.rs
index 254d40f0393..a6aa220ccfa 100644
--- a/components/style/traversal.rs
+++ b/components/style/traversal.rs
@@ -845,7 +845,7 @@ where
                 //
                 // By consequence, any element without data has no descendants with
                 // data.
-                if kid.get_data().is_some() {
+                if kid.has_data() {
                     kid.clear_data();
                     parents.push(kid);
                 }
diff --git a/tests/unit/script/size_of.rs b/tests/unit/script/size_of.rs
index e3107c13290..4b18decc66a 100644
--- a/tests/unit/script/size_of.rs
+++ b/tests/unit/script/size_of.rs
@@ -30,10 +30,10 @@ macro_rules! sizeof_checker (
 
 // Update the sizes here
 sizeof_checker!(size_event_target, EventTarget, 56);
-sizeof_checker!(size_node, Node, 176);
-sizeof_checker!(size_element, Element, 352);
-sizeof_checker!(size_htmlelement, HTMLElement, 368);
-sizeof_checker!(size_div, HTMLDivElement, 368);
-sizeof_checker!(size_span, HTMLSpanElement, 368);
-sizeof_checker!(size_text, Text, 208);
-sizeof_checker!(size_characterdata, CharacterData, 208);
+sizeof_checker!(size_node, Node, 184);
+sizeof_checker!(size_element, Element, 360);
+sizeof_checker!(size_htmlelement, HTMLElement, 376);
+sizeof_checker!(size_div, HTMLDivElement, 376);
+sizeof_checker!(size_span, HTMLSpanElement, 376);
+sizeof_checker!(size_text, Text, 216);
+sizeof_checker!(size_characterdata, CharacterData, 216);