Convert references to FileSystem & Co. into shared pointers (avoid use after free)

shell/src/Main.cpp

 #include <AdblockPlus.h>
 #include <iostream>
 #include <sstream>
 
 #include "GcCommand.h"
 #include "HelpCommand.h"
 #include "FiltersCommand.h"
 #include "SubscriptionsCommand.h"
 #include "MatchesCommand.h"
 
 namespace
 {
-  class CerrErrorCallback : public AdblockPlus::ErrorCallback
-  {
-  public:
-    void operator()(const std::string& message)
-    {
-      std::cerr << "Error: " << message << std::endl;
-    }
-  };
-
   void Add(CommandMap& commands, Command* command)
   {
     commands[command->name] = command;
   }
 
   bool ReadCommandLine(std::string& commandLine)
   {
     std::cout << "> ";
     const bool success = std::getline(std::cin, commandLine);
     if (!success)
       std::cout << std::endl;
     return success;
   }
 
   void ParseCommandLine(const std::string& commandLine, std::string& name,
                         std::string& arguments)
   {
     std::istringstream lineStream(commandLine);
     lineStream >> name;
     std::getline(lineStream, arguments);
   }
 }
 
 int main()
 {
   try
   {
-    AdblockPlus::DefaultFileSystem fileSystem;
-    AdblockPlus::DefaultWebRequest webRequest;
-    CerrErrorCallback errorCallback;
     AdblockPlus::AppInfo appInfo;
     appInfo.version = "1.0";
     appInfo.name = "Adblock Plus Shell";
-    AdblockPlus::JsEngine jsEngine(appInfo, &fileSystem, &webRequest,
-                                   &errorCallback);
+    AdblockPlus::JsEngine jsEngine(appInfo);
     AdblockPlus::FilterEngine filterEngine(jsEngine);
 
     CommandMap commands;
     Add(commands, new GcCommand(jsEngine));
     Add(commands, new HelpCommand(commands));
     Add(commands, new FiltersCommand(filterEngine));
     Add(commands, new SubscriptionsCommand(filterEngine));
     Add(commands, new MatchesCommand(filterEngine));
 
     std::string commandLine;
@@ skipping 15 matching lines @@
         std::cout << error.what() << std::endl;
       }
     }
   }
   catch (const std::exception& e)
   {
     std::cerr << "Exception: " << e.what() << std::endl;
   }
   return 0;
 }