Make CPDF_GeneralState have a CPDF_GeneralStateData

core/fpdfapi/fpdf_page/cpdf_pageobject.cpp

Index: core/fpdfapi/fpdf_page/cpdf_pageobject.cpp
diff --git a/core/fpdfapi/fpdf_page/cpdf_pageobject.cpp b/core/fpdfapi/fpdf_page/cpdf_pageobject.cpp
index 17014c48837da7e4e94529c01b685dcea3d4364d..1ce83a85bc7b9bb63cb6d6d101072b3c0b2cf875 100644
--- a/core/fpdfapi/fpdf_page/cpdf_pageobject.cpp
+++ b/core/fpdfapi/fpdf_page/cpdf_pageobject.cpp
@@ -88,8 +88,7 @@ void CPDF_PageObject::TransformClipPath(CFX_Matrix& matrix) {
 void CPDF_PageObject::TransformGeneralState(CFX_Matrix& matrix) {
   if (!m_GeneralState)
     return;
-  CPDF_GeneralStateData* pGS = m_GeneralState.GetPrivateCopy();
-  pGS->m_Matrix.Concat(matrix);
+  m_GeneralState.GetMutableMatrix()->Concat(matrix);
 }
 
 FX_RECT CPDF_PageObject::GetBBox(const CFX_Matrix* pMatrix) const {