servo: Merge #19660 - style: Stop duplicating slots (from emilio:dupe-slots); r=smaug

Bug: 1427001
Reviewed-by: smaug
MozReview-Commit-ID: Cq647BcOzbe
Source-Repo: https://github.com/servo/servo
Source-Revision: d3f603ecbae8c55062142d3979f433a1b6b903a4

--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : 50a7494bbf13646ba014d3a1ca4c8784986086bb

servo/components/style/gecko/wrapper.rs

@@ -536,8 +536,9 @@ impl<'le> GeckoElement<'le> {
     fn get_extended_slots(
         &self,
     ) -> Option<&structs::FragmentOrElement_nsExtendedDOMSlots> {
-        self.get_dom_slots()
+        self.get_dom_slots().and_then(|s| unsafe {
-            .and_then(|s| unsafe { s.mExtendedSlots.mPtr.as_ref() })
+            (s._base.mExtendedSlots.mPtr as *const structs::FragmentOrElement_nsExtendedDOMSlots).as_ref()
+        })
     }
 
     #[inline]
@@ -592,7 +593,7 @@ impl<'le> GeckoElement<'le> {
     fn get_non_xul_xbl_binding_parent_raw_content(&self) -> *mut nsIContent {
         debug_assert!(!self.is_xul_element());
         self.get_extended_slots()
-            .map_or(ptr::null_mut(), |slots| slots.mBindingParent)
+            .map_or(ptr::null_mut(), |slots| slots._base.mBindingParent)
     }
 
     fn has_xbl_binding_parent(&self) -> bool {