Revert "Make m_pShadingObj a CPDF_Stream instead of CPDF_Object."

core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp

Index: core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
index bd4319df114335dd447bfea5122440a971abe9d2..b12a65a84438098c63bac2e12efaee5760bc6f3f 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_parser.cpp
@@ -1128,9 +1128,10 @@ void CPDF_StreamContentParser::Handle_ShadeFill() {
     bbox = m_BBox;
   }
   if (pShading->m_ShadingType >= 4) {
-    bbox.Intersect(_GetShadingBBox(
-        pShading->m_pShadingObj, pShading->m_ShadingType, &pObj->m_Matrix,
-        pShading->m_pFunctions, pShading->m_nFuncs, pShading->m_pCS));
+    bbox.Intersect(_GetShadingBBox(ToStream(pShading->m_pShadingObj),
+                                   pShading->m_ShadingType, &pObj->m_Matrix,
+                                   pShading->m_pFunctions, pShading->m_nFuncs,
+                                   pShading->m_pCS));
   }
   pObj->m_Left = bbox.left;
   pObj->m_Right = bbox.right;