Bug 1617983 - Re-enable separate privileged about content process for about:home, about:newtab, about:welcome on Nightly. r=NeilDeakin

Differential Revision: https://phabricator.services.mozilla.com/D64376

--HG--
extra : moz-landing-system : lando

browser/app/profile/firefox.js

@@ -503,7 +503,7 @@ pref("browser.tabs.delayHidingAudioPlayingIconMS", 3000);
   // for about: pages. This pref name did not age well: we will have multiple
   // types of privileged content processes, each with different privileges.
   // types of privleged content processes, each with different privleges.
-  pref("browser.tabs.remote.separatePrivilegedContentProcess", false);
+  pref("browser.tabs.remote.separatePrivilegedContentProcess", true);
   // This pref will cause assertions when a remoteType triggers a process switch
   // to a new remoteType it should not be able to trigger.
   pref("browser.tabs.remote.enforceRemoteTypeRestrictions", true);