Issue 4988 - [emscripten] Adjust API for Element Hiding Emulation filters

compiled/ElemHideEmulationFilter.h

 #pragma once
 
 #include <cstddef>
 
 #include "Filter.h"
 #include "ElemHideBase.h"
 
-struct CSSPropertyFilterData
+class ElemHideEmulationFilter : public ElemHideBase
 {
-  String::size_type mPrefixEnd;
-  String::size_type mRegexpStart;
-  String::size_type mRegexpEnd;
-  String::size_type mSuffixStart;
-
-  const DependentString GetSelectorPrefix(const String& text,
-      String::size_type selectorStart) const
-  {
-    return DependentString(text, selectorStart, mPrefixEnd - selectorStart);
-  }
-
-  const DependentString GetRegExpSource(const String& text) const
-  {
-    return DependentString(text, mRegexpStart, mRegexpEnd - mRegexpStart);
-  }
-
-  const DependentString GetSelectorSuffix(const String& text) const
-  {
-    return DependentString(text, mSuffixStart);
-  }
+public:
+  explicit ElemHideEmulationFilter(const String& text,
+      const ElemHideData& data);
 };
-
-struct ElemHideData : ElemHideBaseData, CSSPropertyFilterData
-{
-};
-
-class CSSPropertyFilter: public ElemHideBase
-{
-protected:
-  CSSPropertyFilterData mPropertyData;
-public:
-  explicit CSSPropertyFilter(const String& text, const ElemHideData& data);
-  EMSCRIPTEN_KEEPALIVE OwnedString GetRegExpString() const;
-  EMSCRIPTEN_KEEPALIVE const DependentString GetSelectorPrefix() const
-  {
-    return mPropertyData.GetSelectorPrefix(mText, mData.mSelectorStart);
-  }
-  EMSCRIPTEN_KEEPALIVE const DependentString GetSelectorSuffix() const
-  {
-    return mPropertyData.GetSelectorSuffix(mText);
-  }
-};