Auto merge of #12757 - emilio:stylo, r=bholley,pcwalton

stylo: Stop restyling display: none elements, remove the has_changed hack that made us use ReconstructFrame unconditionally.

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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors

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r? @bholley

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1 files changed, 8 insertions, 0 deletions

diff --git a/components/layout/construct.rs b/components/layout/construct.rs
index 809ecaa406a..33b88f6b8c0 100644
--- a/components/layout/construct.rs
+++ b/components/layout/construct.rs
@@ -1374,12 +1374,20 @@ impl<'a, ConcreteThreadSafeLayoutNode: ThreadSafeLayoutNode>
         // We visit the kids first and reset their HAS_NEWLY_CONSTRUCTED_FLOW flags after checking
         // them.  NOTE: Make sure not to bail out early before resetting all the flags!
         let mut need_to_reconstruct = false;
+
+        // If the node has display: none, it's possible that we haven't even
+        // styled the children once, so we need to bailout early here.
+        if node.style(self.style_context()).get_box().clone_display() == display::T::none {
+            return false;
+        }
+
         for kid in node.children() {
             if kid.flags().contains(HAS_NEWLY_CONSTRUCTED_FLOW) {
                 kid.remove_flags(HAS_NEWLY_CONSTRUCTED_FLOW);
                 need_to_reconstruct = true
             }
         }
+
         if need_to_reconstruct {
             return false
         }