Backed out changeset 44255b7d9b1c (bug 1746524) for causing xpcshell failures on test_ext_userScripts_register.js CLOSED TREE

modules/libpref/init/StaticPrefList.yaml

@@ -1523,7 +1523,7 @@
 # from parent-process BrowsingContexts
 - name: browser.tabs.documentchannel.parent-controlled
   type: bool
-  value: true
+  value: false
   mirror: always
 
 # Testing-only pref which makes data: URIs be loaded in a "web" content process