Bug 1385249 - Reenable the preallocated process. r=mrbkap

browser/app/profile/firefox.js

@@ -1649,10 +1649,7 @@ pref("browser.esedbreader.loglevel", "Error");
 
 pref("browser.laterrun.enabled", false);
 
-// Disable prelaunch in the same way activity-stream is enabled addressing
-// bug 1381804 memory usage until bug 1376895 is fixed.
-// Because of frequent crashes on Beta, it is turned off on all channels, see: bug 1363601.
-pref("dom.ipc.processPrelaunch.enabled", false);
+pref("dom.ipc.processPrelaunch.enabled", true);
 
 pref("browser.migrate.automigrate.enabled", false);
 // 4 here means the suggestion notification will be automatically