Remove FX_DWORD from core/ and delete definition

core/fpdfapi/fpdf_parser/include/cpdf_reference.h

Index: core/fpdfapi/fpdf_parser/include/cpdf_reference.h
diff --git a/core/fpdfapi/fpdf_parser/include/cpdf_reference.h b/core/fpdfapi/fpdf_parser/include/cpdf_reference.h
index f44f1e437b1a53401885c1bd21b01c490c30d4ff..b7d826902bd103b08bbfb6fa2da97063e1cd4d9b 100644
--- a/core/fpdfapi/fpdf_parser/include/cpdf_reference.h
+++ b/core/fpdfapi/fpdf_parser/include/cpdf_reference.h
@@ -31,9 +31,9 @@ class CPDF_Reference : public CPDF_Object {
   const CPDF_Reference* AsReference() const override;
 
   CPDF_IndirectObjectHolder* GetObjList() const { return m_pObjList; }
-  FX_DWORD GetRefObjNum() const { return m_RefObjNum; }
+  uint32_t GetRefObjNum() const { return m_RefObjNum; }
 
-  void SetRef(CPDF_IndirectObjectHolder* pDoc, FX_DWORD objnum);
+  void SetRef(CPDF_IndirectObjectHolder* pDoc, uint32_t objnum);
 
  protected:
   ~CPDF_Reference() override;
@@ -45,7 +45,7 @@ class CPDF_Reference : public CPDF_Object {
   }
 
   CPDF_IndirectObjectHolder* m_pObjList;
-  FX_DWORD m_RefObjNum;
+  uint32_t m_RefObjNum;
 };
 
 #endif  // CORE_FPDFAPI_FPDF_PARSER_INCLUDE_CPDF_REFERENCE_H_