Bug 1727158 - Part 2: Bump processCount.webIsolated to 4 on desktop, r=annyG

Differential Revision: https://phabricator.services.mozilla.com/D125293

modules/libpref/init/all.js

@@ -2480,7 +2480,11 @@ pref("dom.ipc.processCount.privilegedabout", 1);
 pref("dom.ipc.processCount.privilegedmozilla", 1);
 
 // Maximum number of isolated content processes per-origin.
+#ifdef ANDROID
 pref("dom.ipc.processCount.webIsolated", 1);
+#else
+pref("dom.ipc.processCount.webIsolated", 4);
+#endif
 
 // Keep a single privileged about process alive for performance reasons.
 // e.g. we do not want to throw content processes out every time we navigate