Back out the all.js change from Michael Ventnor's patch in bug 416274 to see if it is the cause of a perf regression.

modules/libpref/src/init/all.js

@@ -763,17 +763,7 @@ pref("network.ntlm.send-lm-response", false);
 pref("network.hosts.nntp_server",           "news.mozilla.org");
 
 pref("permissions.default.image",           1); // 1-Accept, 2-Deny, 3-dontAcceptForeign
-
-#ifndef XP_MACOSX
-#ifdef XP_UNIX
-pref("network.proxy.type",                  5);
-#else
 pref("network.proxy.type",                  0);
-#endif
-#else
-pref("network.proxy.type",                  0);
-#endif
-
 pref("network.proxy.ftp",                   "");
 pref("network.proxy.ftp_port",              0);
 pref("network.proxy.gopher",                "");