Create a solid rectangle display list entry for the page background.

Cargo.lock

@@ -5405,7 +5405,7 @@ dependencies = [
 [[package]]
 name = "webrender"
 version = "0.60.0"
-source = "git+https://github.com/servo/webrender#fb1c0cf5ee16724820d004ad77e9f72beeeb7181"
+source = "git+https://github.com/servo/webrender#81703c1274cd4935f82412d4e5819942934d0c96"
 dependencies = [
  "base64 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5446,7 +5446,7 @@ dependencies = [
 [[package]]
 name = "webrender_api"
 version = "0.60.0"
-source = "git+https://github.com/servo/webrender#fb1c0cf5ee16724820d004ad77e9f72beeeb7181"
+source = "git+https://github.com/servo/webrender#81703c1274cd4935f82412d4e5819942934d0c96"
 dependencies = [
  "app_units 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "bincode 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -5468,7 +5468,7 @@ dependencies = [
 [[package]]
 name = "webrender_build"
 version = "0.0.1"
-source = "git+https://github.com/servo/webrender#fb1c0cf5ee16724820d004ad77e9f72beeeb7181"
+source = "git+https://github.com/servo/webrender#81703c1274cd4935f82412d4e5819942934d0c96"
 dependencies = [
  "sha2 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -5620,7 +5620,7 @@ dependencies = [
 [[package]]
 name = "wr_malloc_size_of"
 version = "0.0.1"
-source = "git+https://github.com/servo/webrender#fb1c0cf5ee16724820d004ad77e9f72beeeb7181"
+source = "git+https://github.com/servo/webrender#81703c1274cd4935f82412d4e5819942934d0c96"
 dependencies = [
  "app_units 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.19.8 (registry+https://github.com/rust-lang/crates.io-index)",

components/layout/display_list/builder.rs

@@ -345,7 +345,7 @@ impl<'a> DisplayListBuildState<'a> {
         }
     }
 
-    fn add_display_item(&mut self, display_item: DisplayItem) {
+    pub fn add_display_item(&mut self, display_item: DisplayItem) {
         let items = self
             .items
             .entry(display_item.stacking_context_id())
@@ -374,7 +374,7 @@ impl<'a> DisplayListBuildState<'a> {
             self.processing_scrolling_overflow_element
     }
 
-    fn create_base_display_item(
+    pub fn create_base_display_item(
         &self,
         bounds: Rect<Au>,
         clip_rect: Rect<Au>,

components/layout/sequential.rs

@@ -6,6 +6,7 @@
 
 use crate::context::LayoutContext;
 use crate::display_list::{DisplayListBuildState, StackingContextCollectionState};
+use crate::display_list::items::{self, CommonDisplayItem, DisplayItem, DisplayListSection};
 use crate::floats::SpeculatedFloatPlacement;
 use crate::flow::{Flow, FlowFlags, GetBaseFlow, ImmutableFlowUtils};
 use crate::fragment::{CoordinateSystem, FragmentBorderBoxIterator};
@@ -14,7 +15,7 @@ use crate::incremental::RelayoutMode;
 use crate::traversal::{AssignBSizes, AssignISizes, BubbleISizes, BuildDisplayList};
 use crate::traversal::{InorderFlowTraversal, PostorderFlowTraversal, PreorderFlowTraversal};
 use app_units::Au;
-use euclid::{Point2D, Vector2D};
+use euclid::{Point2D, Rect, Size2D, Vector2D};
 use servo_config::opts;
 use style::servo::restyle_damage::ServoRestyleDamage;
 use webrender_api::units::LayoutPoint;
@@ -72,11 +73,31 @@ pub fn reflow(root: &mut dyn Flow, layout_context: &LayoutContext, relayout_mode
 pub fn build_display_list_for_subtree<'a>(
     flow_root: &mut dyn Flow,
     layout_context: &'a LayoutContext,
+    background_color: webrender_api::ColorF,
+    client_size: Size2D<Au>,
 ) -> DisplayListBuildState<'a> {
     let mut state = StackingContextCollectionState::new(layout_context.id);
     flow_root.collect_stacking_contexts(&mut state);
 
-    let state = DisplayListBuildState::new(layout_context, state);
+    let mut state = DisplayListBuildState::new(layout_context, state);
+
+    // Create a base rectangle for the page background based on the root
+    // background color.
+    let base = state.create_base_display_item(
+        Rect::new(Point2D::new(Au::new(0), Au::new(0)), client_size),
+        Rect::new(Point2D::new(Au::new(0), Au::new(0)), client_size),
+        flow_root.as_block().fragment.node,
+        None,
+        DisplayListSection::BackgroundAndBorders,
+    );
+    state.add_display_item(DisplayItem::Rectangle(CommonDisplayItem::new(
+        base,
+        webrender_api::RectangleDisplayItem {
+            color: background_color,
+            common: items::empty_common_item_properties(),
+        },
+    )));
+
     let mut build_display_list = BuildDisplayList { state: state };
     build_display_list.traverse(flow_root);
     build_display_list.state

components/layout_thread/lib.rs

@@ -1138,8 +1138,13 @@ impl LayoutThread {
                     rw_data.display_list.is_none()
                 {
                     if reflow_goal.needs_display_list() {
-                        let mut build_state =
-                            sequential::build_display_list_for_subtree(layout_root, layout_context);
+                        let background_color = get_root_flow_background_color(layout_root);
+                        let mut build_state = sequential::build_display_list_for_subtree(
+                            layout_root,
+                            layout_context,
+                            background_color,
+                            data.page_clip_rect.size,
+                        );
 
                         debug!("Done building display list.");
 
@@ -1255,7 +1260,7 @@ impl LayoutThread {
                 let mut txn = webrender_api::Transaction::new();
                 txn.set_display_list(
                     webrender_api::Epoch(epoch.0),
-                    Some(get_root_flow_background_color(layout_root)),
+                    None,
                     viewport_size,
                     builder.finalize(),
                     true,