Rename "libchromeos" into "libbrillo"

Renamed libchromeos[-.*] libraries into libbrillo-...

BUG: 24872993
Change-Id: Ibab1623b6a08a55cae3662e941d0d6644ff14df4
diff --git a/brillo/userdb_utils.h b/brillo/userdb_utils.h
index 4377119..8d6dc20 100644
--- a/brillo/userdb_utils.h
+++ b/brillo/userdb_utils.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef LIBCHROMEOS_BRILLO_USERDB_UTILS_H_
-#define LIBCHROMEOS_BRILLO_USERDB_UTILS_H_
+#ifndef LIBBRILLO_BRILLO_USERDB_UTILS_H_
+#define LIBBRILLO_BRILLO_USERDB_UTILS_H_
 
 #include <sys/types.h>
 
@@ -29,4 +29,4 @@
 }  // namespace userdb
 }  // namespace brillo
 
-#endif  // LIBCHROMEOS_BRILLO_USERDB_UTILS_H_
+#endif  // LIBBRILLO_BRILLO_USERDB_UTILS_H_