Bug 520165 - Part11: Fix download manager tests dependancies, r=sdwilsh

toolkit/components/downloads/test/unit/test_history_expiration.js

@@ -121,9 +121,11 @@ function run_test()
   // Set expiration stuff to 0 to make the download expire
   let prefs = Cc["@mozilla.org/preferences-service;1"].
               getService(Ci.nsIPrefBranch);
-  prefs.setIntPref("browser.history_expire_sites", 0);
-  prefs.setIntPref("browser.history_expire_days_min", 0);
-  prefs.setIntPref("browser.history_expire_days", 0);
+  prefs.setIntPref("places.history.expiration.max_pages", 0);
+
+  // Force a history expiration.
+  let expire = Cc["@mozilla.org/places/expiration;1"].getService(Ci.nsIObserver);
+  expire.observe(null, "places-debug-start-expiration", null);
 
   // Expiration happens on a timeout, about 3.5s after we set the pref
   do_test_pending();