Issue 4125 - [emscripten] Convert filter classes to C++

compiled/Filter.h

-#ifndef ADBLOCK_PLUS_FILTER_H
-#define ADBLOCK_PLUS_FILTER_H
+#pragma once
 
 #include <vector>
 
 #include "String.h"
 #include "intrusive_ptr.h"
 #include "debug.h"
 
 class Filter : public ref_counted
 {
 protected:
-  String mText;
+  OwnedString mText;
 
 public:
-  explicit Filter(const String& text);
-  virtual ~Filter();
-
-  /* TODO
-  std::vector<Subscription> subscriptions;
-  */
-
-  const String GetText() const
-  {
-    return mText;
-  }
-
   enum Type
   {
     UNKNOWN = 0,
     INVALID = 1,
     COMMENT = 2,
     BLOCKING = 3,
     WHITELIST = 4,
     ELEMHIDE = 5,
     ELEMHIDEEXCEPTION = 6,
     CSSPROPERTY = 7,
   };
 
-  virtual Type GetType() const = 0;
+  explicit Filter(Type type, const String& text);
+  ~Filter();
 
-  virtual String Serialize() const;
+  Type mType;
 
-  static Filter* FromText(const String& text);
-  static String Normalize(String& text);
+  /* TODO
+  std::vector<Subscription> mSubscriptions;
+  */
+
+  EMSCRIPTEN_KEEPALIVE const String& GetText() const
+  {
+    return mText;
+  }
+
+  EMSCRIPTEN_KEEPALIVE OwnedString Serialize() const;
+
+  static EMSCRIPTEN_KEEPALIVE Filter* FromText(DependentString& text);
 };
 
 typedef intrusive_ptr<Filter> FilterPtr;
-
-#endif