Put pre- and auto-login behind flags.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
===================================================================
--- chrome/common/chrome_switches.cc	(revision 98807)
+++ chrome/common/chrome_switches.cc	(working copy)
@@ -406,6 +406,11 @@
 // automatically due to privacy concerns.
 const char kEnableAutofillFeedback[]        = "enable-autofill-feedback";
 
+// Enables the pre- and auto-login features.  When a user signs in to sync,
+// the browser's cookie jar is pre-filled with GAIA cookies.  When the user
+// visits a GAIA login page, an info bar can help the user login.
+const char kEnableAutologin[]               = "enable-autologin";
+
 // This flag enables UI for clearing server data.  Temporarily in place
 // until there's a server endpoint deployed.
 const char kEnableClearServerData[]         = "enable-clear-server-data";