MD Bookmarks: Support policies for disabling bookmark editing

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();
 
+  bool CanEditBookmarks();
+  void HandleGetCanEditBookmarks(const base::ListValue* args);
+  void UpdateCanEditBookmarks();
+
   // 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_