Auto merge of #29748 - Loirooriol:sync, r=mrobinson

Backport several style changes from Gecko

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- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #___ (GitHub issue number if applicable)

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components/layout_2020/dom_traversal.rs

@@ -354,9 +354,9 @@ where
                             attr_val.map_or("".to_string(), |s| s.to_string()),
                         ));
                     },
-                    ContentItem::Url(image_url) => {
+                    ContentItem::Image(image) => {
                         if let Some(replaced_content) =
-                            ReplacedContent::from_image_url(element, context, image_url)
+                            ReplacedContent::from_image(element, context, image)
                         {
                             vec.push(PseudoElementContentItem::Replaced(replaced_content));
                         }

components/layout_2020/replaced.rs

@@ -21,6 +21,7 @@ use std::fmt;
 use std::sync::{Arc, Mutex};
 use style::properties::ComputedValues;
 use style::servo::url::ComputedUrl;
+use style::values::computed::image::Image as ComputedImage;
 use style::values::computed::{Length, LengthOrAuto};
 use style::values::CSSFloat;
 use style::Zero;
@@ -184,6 +185,17 @@ impl ReplacedContent {
         None
     }
 
+    pub fn from_image<'dom>(
+        element: impl NodeExt<'dom>,
+        context: &LayoutContext,
+        image: &ComputedImage,
+    ) -> Option<Self> {
+        match image {
+            ComputedImage::Url(image_url) => Self::from_image_url(element, context, image_url),
+            _ => None, // TODO
+        }
+    }
+
     fn flow_relative_intrinsic_size(&self, style: &ComputedValues) -> Vec2<Option<Length>> {
         let intrinsic_size = PhysicalSize::new(self.intrinsic.width, self.intrinsic.height);
         Vec2::from_physical_size(&intrinsic_size, style.writing_mode)