chrome: Support customization of context menus (see issue #2969)

libcef/browser/chrome/chrome_context_menu_handler.h

@@ -0,0 +1,16 @@
+// Copyright (c) 2021 The Chromium Embedded Framework 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 CEF_LIBCEF_BROWSER_CHROME_CHROME_CONTEXT_MENU_HANDLER_H_
+#define CEF_LIBCEF_BROWSER_CHROME_CHROME_CONTEXT_MENU_HANDLER_H_
+#pragma once
+
+namespace context_menu {
+
+// Register the context menu created callback.
+void RegisterMenuCreatedCallback();
+
+}  // namespace context_menu
+
+#endif  // CEF_LIBCEF_BROWSER_CHROME_CHROME_CONTEXT_MENU_HANDLER_H_