Make CPDF_Path have a CFX_Path rather than inheriting

fpdfsdk/fxedit/fxet_edit.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 "fpdfsdk/fxedit/include/fxet_edit.h"
 
 #include <algorithm>
 
@@ skipping 119 matching lines @@
                                           nullptr, &ro);
       }
     }
   }
 }
 
 void AddRectToPageObjects(CPDF_PageObjectHolder* pObjectHolder,
                           FX_COLORREF crFill,
                           const CFX_FloatRect& rcFill) {
   std::unique_ptr<CPDF_PathObject> pPathObj(new CPDF_PathObject);
-  CFX_PathData* pPathData = pPathObj->m_Path.GetPrivateCopy();
-  pPathData->AppendRect(rcFill.left, rcFill.bottom, rcFill.right, rcFill.top);
+  pPathObj->m_Path.AppendRect(rcFill.left, rcFill.bottom, rcFill.right,
+                              rcFill.top);
 
   FX_FLOAT rgb[3];
   rgb[0] = FXARGB_R(crFill) / 255.0f;
   rgb[1] = FXARGB_G(crFill) / 255.0f;
   rgb[2] = FXARGB_B(crFill) / 255.0f;
   pPathObj->m_ColorState.SetFillColor(
       CPDF_ColorSpace::GetStockCS(PDFCS_DEVICERGB), rgb, 3);
 
   pPathObj->m_FillType = FXFILL_ALTERNATE;
   pPathObj->m_bStroke = FALSE;
@@ skipping 2904 matching lines @@
 int32_t CFX_Edit_RectArray::GetSize() const {
   return m_Rects.GetSize();
 }
 
 CFX_FloatRect* CFX_Edit_RectArray::GetAt(int32_t nIndex) const {
   if (nIndex < 0 || nIndex >= m_Rects.GetSize())
     return nullptr;
 
   return m_Rects.GetAt(nIndex);
 }