diff --git a/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp b/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
index 1dfef98..9ce49f2 100644
--- a/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
+++ b/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
@@ -228,9 +228,8 @@
     std::ostringstream* buf,
     const CPDF_PageObject* pPageObj,
     const CPDF_ContentMarks* pPrev) {
-  const CPDF_ContentMarks* pNext = &pPageObj->m_ContentMarks;
-
-  size_t first_different = pPrev->FindFirstDifference(pNext);
+  const CPDF_ContentMarks* pNext = pPageObj->GetContentMarks();
+  const size_t first_different = pPrev->FindFirstDifference(pNext);
 
   // Close all marks that are in prev but not in next.
   // Technically we should iterate backwards to close from the top to the
diff --git a/core/fpdfapi/page/cpdf_occontext.cpp b/core/fpdfapi/page/cpdf_occontext.cpp
index 62aad99..56592cb 100644
--- a/core/fpdfapi/page/cpdf_occontext.cpp
+++ b/core/fpdfapi/page/cpdf_occontext.cpp
@@ -183,8 +183,9 @@
 }
 
 bool CPDF_OCContext::CheckObjectVisible(const CPDF_PageObject* pObj) const {
-  for (size_t i = 0; i < pObj->m_ContentMarks.CountItems(); ++i) {
-    const CPDF_ContentMarkItem* item = pObj->m_ContentMarks.GetItem(i);
+  const CPDF_ContentMarks* pMarks = pObj->GetContentMarks();
+  for (size_t i = 0; i < pMarks->CountItems(); ++i) {
+    const CPDF_ContentMarkItem* item = pMarks->GetItem(i);
     if (item->GetName() == "OC" &&
         item->GetParamType() == CPDF_ContentMarkItem::kPropertiesDict &&
         !CheckOCGVisible(item->GetParam())) {
diff --git a/core/fpdfapi/page/cpdf_pageobject.h b/core/fpdfapi/page/cpdf_pageobject.h
index f840214..a8ce3e9 100644
--- a/core/fpdfapi/page/cpdf_pageobject.h
+++ b/core/fpdfapi/page/cpdf_pageobject.h
@@ -63,6 +63,12 @@
   FX_RECT GetBBox() const;
   FX_RECT GetTransformedBBox(const CFX_Matrix& matrix) const;
 
+  CPDF_ContentMarks* GetContentMarks() { return &m_ContentMarks; }
+  const CPDF_ContentMarks* GetContentMarks() const { return &m_ContentMarks; }
+  void SetContentMarks(const CPDF_ContentMarks& marks) {
+    m_ContentMarks = marks;
+  }
+
   // Get what content stream the object was parsed from in its page. This number
   // is the index of the content stream in the "Contents" array, or 0 if there
   // is a single content stream. If the object is newly created,
@@ -75,7 +81,6 @@
     m_ContentStream = new_content_stream;
   }
 
-  CPDF_ContentMarks m_ContentMarks;
 
  protected:
   void CopyData(const CPDF_PageObject* pSrcObject);
@@ -83,6 +88,7 @@
   CFX_FloatRect m_Rect;
 
  private:
+  CPDF_ContentMarks m_ContentMarks;
   bool m_bDirty = false;
   int32_t m_ContentStream;
 };
diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.cpp b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
index 2039a57..9435f40 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
@@ -402,7 +402,7 @@
                                                 bool bGraph) {
   pObj->m_GeneralState = m_pCurStates->m_GeneralState;
   pObj->m_ClipPath = m_pCurStates->m_ClipPath;
-  pObj->m_ContentMarks = *m_ContentMarksStack.top();
+  pObj->SetContentMarks(*m_ContentMarksStack.top());
   if (bColor) {
     pObj->m_ColorState = m_pCurStates->m_ColorState;
   }
diff --git a/core/fpdftext/cpdf_textpage.cpp b/core/fpdftext/cpdf_textpage.cpp
index f0f7034..f4bf8e2 100644
--- a/core/fpdftext/cpdf_textpage.cpp
+++ b/core/fpdftext/cpdf_textpage.cpp
@@ -832,7 +832,8 @@
 
 CPDF_TextPage::MarkedContentState CPDF_TextPage::PreMarkedContent(
     const CPDF_TextObject* pTextObj) {
-  size_t nContentMarks = pTextObj->m_ContentMarks.CountItems();
+  const CPDF_ContentMarks* pMarks = pTextObj->GetContentMarks();
+  const size_t nContentMarks = pMarks->CountItems();
   if (nContentMarks == 0)
     return MarkedContentState::kPass;
 
@@ -840,7 +841,7 @@
   bool bExist = false;
   const CPDF_Dictionary* pDict = nullptr;
   for (size_t i = 0; i < nContentMarks; ++i) {
-    const CPDF_ContentMarkItem* item = pTextObj->m_ContentMarks.GetItem(i);
+    const CPDF_ContentMarkItem* item = pMarks->GetItem(i);
     pDict = item->GetParam();
     if (!pDict)
       continue;
@@ -854,9 +855,9 @@
     return MarkedContentState::kPass;
 
   if (m_pPrevTextObj) {
-    const CPDF_ContentMarks& marks = m_pPrevTextObj->m_ContentMarks;
-    if (marks.CountItems() == nContentMarks &&
-        marks.GetItem(nContentMarks - 1)->GetParam() == pDict) {
+    const CPDF_ContentMarks* pPrevMarks = m_pPrevTextObj->GetContentMarks();
+    if (pPrevMarks->CountItems() == nContentMarks &&
+        pPrevMarks->GetItem(nContentMarks - 1)->GetParam() == pDict) {
       return MarkedContentState::kDone;
     }
   }
@@ -891,13 +892,11 @@
 
 void CPDF_TextPage::ProcessMarkedContent(const TransformedTextObject& obj) {
   const CPDF_TextObject* pTextObj = obj.m_pTextObj.Get();
-  size_t nContentMarks = pTextObj->m_ContentMarks.CountItems();
-  if (nContentMarks == 0)
-    return;
-
+  const CPDF_ContentMarks* pMarks = pTextObj->GetContentMarks();
+  const size_t nContentMarks = pMarks->CountItems();
   WideString actText;
   for (size_t n = 0; n < nContentMarks; ++n) {
-    const CPDF_ContentMarkItem* item = pTextObj->m_ContentMarks.GetItem(n);
+    const CPDF_ContentMarkItem* item = pMarks->GetItem(n);
     const CPDF_Dictionary* pDict = item->GetParam();
     if (pDict)
       actText = pDict->GetUnicodeTextFor("ActualText");
diff --git a/fpdfsdk/fpdf_editimg.cpp b/fpdfsdk/fpdf_editimg.cpp
index f98f223..9f86f30 100644
--- a/fpdfsdk/fpdf_editimg.cpp
+++ b/fpdfsdk/fpdf_editimg.cpp
@@ -364,7 +364,8 @@
   if (!pImg)
     return false;
 
-  metadata->marked_content_id = pImgObj->m_ContentMarks.GetMarkedContentID();
+  metadata->marked_content_id =
+      pImgObj->GetContentMarks()->GetMarkedContentID();
 
   const int nPixelWidth = pImg->GetPixelWidth();
   const int nPixelHeight = pImg->GetPixelHeight();
diff --git a/fpdfsdk/fpdf_editpage.cpp b/fpdfsdk/fpdf_editpage.cpp
index 6e71924..5c5774e 100644
--- a/fpdfsdk/fpdf_editpage.cpp
+++ b/fpdfsdk/fpdf_editpage.cpp
@@ -134,7 +134,7 @@
                             FPDF_PAGEOBJECTMARK mark) {
   const CPDF_ContentMarkItem* pMarkItem =
       CPDFContentMarkItemFromFPDFPageObjectMark(mark);
-  return pMarkItem && pPageObj->m_ContentMarks.ContainsItem(pMarkItem);
+  return pMarkItem && pPageObj->GetContentMarks()->ContainsItem(pMarkItem);
 }
 
 CPDF_FormObject* CPDFFormObjectFromFPDFPageObject(FPDF_PAGEOBJECT page_object) {
@@ -294,7 +294,7 @@
   if (!pPageObj)
     return -1;
 
-  return pPageObj->m_ContentMarks.CountItems();
+  return pPageObj->GetContentMarks()->CountItems();
 }
 
 FPDF_EXPORT FPDF_PAGEOBJECTMARK FPDF_CALLCONV
@@ -303,11 +303,11 @@
   if (!pPageObj)
     return nullptr;
 
-  auto& mark = pPageObj->m_ContentMarks;
-  if (index >= mark.CountItems())
+  CPDF_ContentMarks* pMarks = pPageObj->GetContentMarks();
+  if (index >= pMarks->CountItems())
     return nullptr;
 
-  return FPDFPageObjectMarkFromCPDFContentMarkItem(mark.GetItem(index));
+  return FPDFPageObjectMarkFromCPDFContentMarkItem(pMarks->GetItem(index));
 }
 
 FPDF_EXPORT FPDF_PAGEOBJECTMARK FPDF_CALLCONV
@@ -316,11 +316,12 @@
   if (!pPageObj)
     return nullptr;
 
-  auto& mark = pPageObj->m_ContentMarks;
-  mark.AddMark(name);
-  unsigned long index = mark.CountItems() - 1;
+  CPDF_ContentMarks* pMarks = pPageObj->GetContentMarks();
+  pMarks->AddMark(name);
   pPageObj->SetDirty(true);
-  return FPDFPageObjectMarkFromCPDFContentMarkItem(mark.GetItem(index));
+
+  const unsigned long index = pMarks->CountItems() - 1;
+  return FPDFPageObjectMarkFromCPDFContentMarkItem(pMarks->GetItem(index));
 }
 
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV
@@ -331,11 +332,11 @@
   if (!pPageObj || !pMarkItem)
     return false;
 
-  bool result = pPageObj->m_ContentMarks.RemoveMark(pMarkItem);
-  if (result)
-    pPageObj->SetDirty(true);
+  if (!pPageObj->GetContentMarks()->RemoveMark(pMarkItem))
+    return false;
 
-  return result;
+  pPageObj->SetDirty(true);
+  return true;
 }
 
 FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV