Don't compare the vtable pointers anymore when unrooting stuff

components/script/dom/bindings/root.rs

@@ -262,7 +262,10 @@ impl RootCollection {
     unsafe fn unroot(&self, object: *const dyn JSTraceable) {
         debug_assert!(thread_state::get().is_script());
         let roots = &mut *self.roots.get();
-        match roots.iter().rposition(|r| *r == object) {
+        match roots
+            .iter()
+            .rposition(|r| *r as *const () == object as *const ())
+        {
             Some(idx) => {
                 roots.remove(idx);
             },

components/script/dom/bindings/trace.rs

@@ -891,7 +891,11 @@ impl RootedTraceableSet {
     unsafe fn remove(traceable: *const dyn JSTraceable) {
         ROOTED_TRACEABLES.with(|ref traceables| {
             let mut traceables = traceables.borrow_mut();
-            let idx = match traceables.set.iter().rposition(|x| *x == traceable) {
+            let idx = match traceables
+                .set
+                .iter()
+                .rposition(|x| *x as *const () == traceable as *const ())
+            {
                 Some(idx) => idx,
                 None => unreachable!(),
             };