Stop casting struct CFXJSE_ArgumentsImpl to unrelated class CFXJSE_Arguments

xfa/fxjse/cfxjse_arguments.h

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #ifndef XFA_FXJSE_CFXJSE_ARGUMENTS_H_
 #define XFA_FXJSE_CFXJSE_ARGUMENTS_H_
 
 #include "xfa/fxjse/include/fxjse.h"
 
 class CFXJSE_Arguments {
  public:
+  CFXJSE_Arguments(const v8::FunctionCallbackInfo<v8::Value>* pInfo,
+                   CFXJSE_Value* pRetValue)
+      : m_pInfo(pInfo), m_pRetValue(pRetValue) {}
+
   v8::Isolate* GetRuntime() const;
   int32_t GetLength() const;
   std::unique_ptr<CFXJSE_Value> GetValue(int32_t index) const;
   FX_BOOL GetBoolean(int32_t index) const;
   int32_t GetInt32(int32_t index) const;
   FX_FLOAT GetFloat(int32_t index) const;
   CFX_ByteString GetUTF8String(int32_t index) const;
   void* GetObject(int32_t index, CFXJSE_Class* pClass = nullptr) const;
   CFXJSE_Value* GetReturnValue();
+
+ private:
+  const v8::FunctionCallbackInfo<v8::Value>* m_pInfo;
+  CFXJSE_Value* m_pRetValue;
 };
 
 #endif  // XFA_FXJSE_CFXJSE_ARGUMENTS_H_