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

shell/src/Main.cpp

Index: shell/src/Main.cpp
===================================================================
--- a/shell/src/Main.cpp
+++ b/shell/src/Main.cpp
@@ -5,25 +5,16 @@
 #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 << "> ";
@@ -41,24 +32,20 @@ namespace
     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));