Auto merge of #26477 - mrobinson:layout-2020-get-computed-value, r=jdm

Add support for getComputedStyle() to layout_2020

These changes add support for `getComputedStyle()` to layout_2020.

---
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] There are tests for these changes

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1 files changed, 8 insertions, 2 deletions

diff --git a/components/layout_thread_2020/lib.rs b/components/layout_thread_2020/lib.rs
index 7639c2dc70c..42a5a4d3e00 100644
--- a/components/layout_thread_2020/lib.rs
+++ b/components/layout_thread_2020/lib.rs
@@ -1194,8 +1194,14 @@ impl LayoutThread {
                 },
                 &QueryMsg::ResolvedStyleQuery(node, ref pseudo, ref property) => {
                     let node = unsafe { ServoLayoutNode::new(&node) };
-                    rw_data.resolved_style_response =
-                        process_resolved_style_request(context, node, pseudo, property);
+                    let fragment_tree = self.fragment_tree_root.borrow().clone();
+                    rw_data.resolved_style_response = process_resolved_style_request(
+                        context,
+                        node,
+                        pseudo,
+                        property,
+                        fragment_tree,
+                    );
                 },
                 &QueryMsg::OffsetParentQuery(node) => {
                     rw_data.offset_parent_response = process_offset_parent_query(node);