Adding notifications for new sync types.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index d49a5f17176fb402d398a412d58ab9261b16ef82..ff5cc9473101deec905f6dd865cba17d679ae035 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -1256,6 +1256,11 @@ const char kSyncSuppressStart[] = "sync.suppress_start";
 // migrated to the new model.
 const char kAutofillProfileMigrated[] = "sync.autofill_migrated";
 
+// String representation of the currently acknowledged set of sync types,
+// used to figure out if a new sync type has rolled out so we can notify the
+// user.
+const char kAcknowledgedSyncTypes[] = "sync.acknowledged_types";
+
 // A string that can be used to restore sync encryption infrastructure on
 // startup so that the user doesn't need to provide credentials on each start.
 const char kEncryptionBootstrapToken[] = "sync.encryption_bootstrap_token";