[sync] Add constexpr to EnumSet

components/reading_list/core/reading_list_switches.h

Index: components/reading_list/core/reading_list_switches.h
diff --git a/components/reading_list/core/reading_list_switches.h b/components/reading_list/core/reading_list_switches.h
deleted file mode 100644
index c99231c5deff612fe442bc4a02bd9d2217727333..0000000000000000000000000000000000000000
--- a/components/reading_list/core/reading_list_switches.h
+++ /dev/null
@@ -1,15 +0,0 @@
-// Copyright 2016 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_READING_LIST_CORE_READING_LIST_SWITCHES_H_
-#define COMPONENTS_READING_LIST_CORE_READING_LIST_SWITCHES_H_
-
-namespace reading_list {
-namespace switches {
-// Whether Reading List is enabled on this device.
-bool IsReadingListEnabled();
-}  // namespace switches
-}  // namespace reading_list
-
-#endif  // COMPONENTS_READING_LIST_CORE_READING_LIST_SWITCHES_H_