Issue 6477 - separate done and error callbacks in IFileSystem::Read

src/DefaultFileSystem.h

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 36 matching lines @@
     std::string Resolve(const std::string& fileName) const;
   protected:
     std::string basePath;
   };
 
   class DefaultFileSystem : public IFileSystem
   {
   public:
     explicit DefaultFileSystem(const Scheduler& scheduler, std::unique_ptr<DefaultFileSystemSync> syncImpl);
     void Read(const std::string& fileName,
-              const ReadCallback& callback) const override;
+              const ReadCallback& doneCallback,
+              const Callback& errorCallback) const override;
     void Write(const std::string& fileName,
                const IOBuffer& data,
                const Callback& callback) override;
     void Move(const std::string& fromFileName,
               const std::string& toFileName,
               const Callback& callback) override;
     void Remove(const std::string& fileName, const Callback& callback) override;
     void Stat(const std::string& fileName,
               const StatCallback& callback) const override;
 
   private:
     // Returns the absolute path to a file.
     std::string Resolve(const std::string& fileName) const;
     Scheduler scheduler;
     std::unique_ptr<DefaultFileSystemSync> syncImpl;
   };
 }
 
 #endif