--- src/components/content_settings/core/browser/cookie_settings.cc~	2015-09-02 11:00:33.000000000 +0000
+++ src/components/content_settings/core/browser/cookie_settings.cc	2015-09-03 09:30:37.497315300 +0000
@@ -82,7 +82,7 @@
 void CookieSettings::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(
-      prefs::kBlockThirdPartyCookies, false,
+      prefs::kBlockThirdPartyCookies, true,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 }