Make m_pShadingObj a CPDF_Stream instead of CPDF_Object.

core/src/fpdfapi/fpdf_render/fpdf_render_pattern.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 "../../../include/fpdfapi/fpdf_render.h"
 #include "../../../include/fpdfapi/fpdf_pageobj.h"
 #include "../../../include/fxge/fx_ge.h"
 #include "../fpdf_page/pageint.h"
@@ skipping 863 matching lines @@
       break;
     case 2:
       DrawAxialShading(pBitmap, &FinalMatrix, pDict, pFuncs, nFuncs,
                        pColorSpace, alpha);
       break;
     case 3:
       DrawRadialShading(pBitmap, &FinalMatrix, pDict, pFuncs, nFuncs,
                         pColorSpace, alpha);
       break;
     case 4: {
-      DrawFreeGouraudShading(pBitmap, &FinalMatrix,
-                             ToStream(pPattern->m_pShadingObj), pFuncs, nFuncs,
-                             pColorSpace, alpha);
+      DrawFreeGouraudShading(pBitmap, &FinalMatrix, pPattern->m_pShadingObj,
+                             pFuncs, nFuncs, pColorSpace, alpha);
     } break;
     case 5: {
-      DrawLatticeGouraudShading(pBitmap, &FinalMatrix,
-                                ToStream(pPattern->m_pShadingObj), pFuncs,
-                                nFuncs, pColorSpace, alpha);
+      DrawLatticeGouraudShading(pBitmap, &FinalMatrix, pPattern->m_pShadingObj,
+                                pFuncs, nFuncs, pColorSpace, alpha);
     } break;
     case 6:
     case 7: {
       DrawCoonPatchMeshes(pPattern->m_ShadingType - 6, pBitmap, &FinalMatrix,
-                          ToStream(pPattern->m_pShadingObj), pFuncs, nFuncs,
-                          pColorSpace, fill_mode, alpha);
+                          pPattern->m_pShadingObj, pFuncs, nFuncs, pColorSpace,
+                          fill_mode, alpha);
     } break;
   }
   if (bAlphaMode) {
     pBitmap->LoadChannel(FXDIB_Red, pBitmap, FXDIB_Alpha);
   }
   if (m_Options.m_ColorMode == RENDER_COLOR_GRAY) {
     pBitmap->ConvertColorScale(m_Options.m_ForeColor, m_Options.m_BackColor);
   }
   buffer.OutputToDevice();
 }
@@ skipping 295 matching lines @@
     }
   }
   if (bStroke) {
     CPDF_Color& StrokeColor = *pPathObj->m_ColorState.GetStrokeColor();
     if (StrokeColor.m_pCS && StrokeColor.m_pCS->GetFamily() == PDFCS_PATTERN) {
       DrawPathWithPattern(pPathObj, pObj2Device, &StrokeColor, TRUE);
       bStroke = FALSE;
     }
   }
 }