Make m_pShadingObj a CPDF_Stream instead of CPDF_Object.

core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp

Index: core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
index 4ed6c0767581d0824ce0a1352c2d6e4c14246018..015f1a3166df010287e3be3faad4b9ca97321b1d 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_pattern.cpp
@@ -881,20 +881,18 @@ void CPDF_RenderStatus::DrawShading(CPDF_ShadingPattern* pPattern,
                         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) {