Clean up CPDF_Page.

core/fpdfapi/fpdf_edit/fpdf_edit_doc.cpp

 // Copyright 2014 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
 
 #include <limits.h>
 
 #include <set>
 #include <vector>
@@ skipping 1101 matching lines @@
   int nPages = pPages->GetIntegerBy("Count");
   if (iPage < 0 || iPage >= nPages)
     return;
 
   std::set<CPDF_Dictionary*> stack = {pPages};
   if (InsertDeletePDFPage(this, pPages, iPage, nullptr, FALSE, &stack) < 0)
     return;
 
   m_PageList.RemoveAt(iPage);
 }
-
-void FPDFAPI_FlatPageAttr(CPDF_Dictionary* pPageDict,
-                          const CFX_ByteStringC& name) {
-  if (pPageDict->KeyExist(name)) {
-    return;
-  }
-  CPDF_Object* pObj = FPDFAPI_GetPageAttr(pPageDict, name);
-  if (pObj) {
-    pPageDict->SetAt(name, pObj->Clone());
-  }
-}