Backed out changeset 3152110c63b5 (bug 1868374) as requested because it is not yet ready for shipping to release.

modules/libpref/init/StaticPrefList.yaml

@@ -8197,7 +8197,7 @@
 # Whether content-box and stroke-box are enabled for transform-box.
 - name: layout.css.transform-box-content-stroke.enabled
   type: RelaxedAtomicBool
-  value: true
+  value: @IS_NIGHTLY_BUILD@
   mirror: always
   rust: true