Bug 1632098 - P3. Enable the ParentProcessDocumentChannel. r=mattwoodrow

Differential Revision: https://phabricator.services.mozilla.com/D72297

modules/libpref/init/StaticPrefList.yaml

@@ -994,16 +994,17 @@
   value: true
   mirror: always
 
+# If set, use DocumentChannel with parent process' sDocShell
 - name: browser.tabs.documentchannel.ppdc
   type: bool
-  value: false
+  value: true
   mirror: always
 
 # If set, use DocumentChannel to directly initiate loads from
 # parent-process BrowsingContexts
 - name: browser.tabs.documentchannel.parent-initiated
   type: bool
-  value: true 
+  value: true
   mirror: always
 
 - name: browser.tabs.remote.desktopbehavior