MD Bookmarks: Disable 'Open in Incognito Window' when Incognito is disabled

chrome/browser/ui/webui/md_bookmarks/bookmarks_message_handler.h

+// Copyright 2017 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 CHROME_BROWSER_UI_WEBUI_MD_BOOKMARKS_BOOKMARKS_MESSAGE_HANDLER_H_
+#define CHROME_BROWSER_UI_WEBUI_MD_BOOKMARKS_BOOKMARKS_MESSAGE_HANDLER_H_
+
+#include "components/prefs/pref_change_registrar.h"
+#include "content/public/browser/web_ui_message_handler.h"
+
+namespace base {
+class ListValue;
+};
+
+class BookmarksMessageHandler : public content::WebUIMessageHandler {
+ public:
+  BookmarksMessageHandler();
+  ~BookmarksMessageHandler() override;
+
+ private:
+  int GetIncognitoAvailability();
+  void HandleGetIncognitoAvailability(const base::ListValue* args);
+  void UpdateIncognitoAvailability();
+
+  // content::WebUIMessageHandler:
+  void RegisterMessages() override;
+  void OnJavascriptAllowed() override;
+  void OnJavascriptDisallowed() override;
+
+  PrefChangeRegistrar pref_change_registrar_;
+
+  DISALLOW_COPY_AND_ASSIGN(BookmarksMessageHandler);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_MD_BOOKMARKS_BOOKMARKS_MESSAGE_HANDLER_H_