Remove the very old code that migrated password data from the WebDataService to PasswordStore.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
===================================================================
--- chrome/common/pref_names.cc	(revision 133948)
+++ chrome/common/pref_names.cc	(working copy)
@@ -1554,10 +1554,6 @@
 // corresponding access token.
 const char kGeolocationAccessToken[] = "geolocation.access_token";
 
-// Whether PasswordForms have been migrated from the WedDataService to the
-// LoginDatabase.
-const char kLoginDatabaseMigrated[] = "login_database.migrated";
-
 // Boolean that indicates whether to allow firewall traversal while trying to
 // establish the initial connection from the client or host.
 const char kRemoteAccessHostFirewallTraversal[] =