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

compiled/CSSPropertyFilter.h

 #pragma once
 
 #include <cstddef>
 
 #include "Filter.h"
 #include "ElemHideBase.h"
 
 struct CSSPropertyFilterData
 {
   String::size_type mPrefixEnd;
@@ skipping 15 matching lines @@
   const DependentString GetSelectorSuffix(const String& text) const
   {
     return DependentString(text, mSuffixStart);
   }
 };
 
 struct ElemHideData : ElemHideBaseData, CSSPropertyFilterData
 {
 };
 
-class CSSPropertyFilter: public ElemHideBase, protected CSSPropertyFilterData
+class CSSPropertyFilter: public ElemHideBase
 {
+protected:
+  CSSPropertyFilterData mPropertyData;
 public:
-  CSSPropertyFilter(const String& text, const ElemHideData& data);
-  Type GetType() const override;
+  explicit CSSPropertyFilter(const String& text, const ElemHideData& data);
   EMSCRIPTEN_KEEPALIVE OwnedString GetRegExpString() const;
   EMSCRIPTEN_KEEPALIVE const DependentString GetSelectorPrefix() const
   {
-    return CSSPropertyFilterData::GetSelectorPrefix(mText, mSelectorStart);
+    return mPropertyData.GetSelectorPrefix(mText, mData.mSelectorStart);
   }
   EMSCRIPTEN_KEEPALIVE const DependentString GetSelectorSuffix() const
   {
-    return CSSPropertyFilterData::GetSelectorSuffix(mText);
+    return mPropertyData.GetSelectorSuffix(mText);
   }
 };