Move tracked prefs into services/preferences/tracked.

components/user_prefs/tracked/pref_names.h

Index: components/user_prefs/tracked/pref_names.h
diff --git a/components/user_prefs/tracked/pref_names.h b/components/user_prefs/tracked/pref_names.h
deleted file mode 100644
index 80aa6bf5d0739ff1897864911f591fad2a8f6033..0000000000000000000000000000000000000000
--- a/components/user_prefs/tracked/pref_names.h
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef COMPONENTS_USER_PREFS_TRACKED_PREF_NAMES_H_
-#define COMPONENTS_USER_PREFS_TRACKED_PREF_NAMES_H_
-
-namespace user_prefs {
-
-extern const char kPreferenceResetTime[];
-
-}  // namespace user_prefs
-
-#endif  // COMPONENTS_USER_PREFS_TRACKED_PREF_NAMES_H_