5 files changed, 20 insertions, 18 deletions

diff --git a/core/fpdfapi/page/cpdf_contentmark.cpp b/core/fpdfapi/page/cpdf_contentmark.cpp
index c54ef55b1f..e17a30560f 100644
--- a/core/fpdfapi/page/cpdf_contentmark.cpp
+++ b/core/fpdfapi/page/cpdf_contentmark.cpp
@@ -22,6 +22,7 @@ size_t CPDF_ContentMark::CountItems() const {
 }
 
 const CPDF_ContentMarkItem& CPDF_ContentMark::GetItem(size_t i) const {
+  ASSERT(i < CountItems());
   return m_Ref.GetObject()->GetItem(i);
 }
 
@@ -31,7 +32,7 @@ int CPDF_ContentMark::GetMarkedContentID() const {
 }
 
 void CPDF_ContentMark::AddMark(const ByteString& name,
-                               CPDF_Dictionary* pDict,
+                               const CPDF_Dictionary* pDict,
                                bool bDirect) {
   m_Ref.GetPrivateCopy()->AddMark(name, pDict, bDirect);
 }
@@ -68,7 +69,7 @@ int CPDF_ContentMark::MarkData::GetMarkedContentID() const {
 }
 
 void CPDF_ContentMark::MarkData::AddMark(const ByteString& name,
-                                         CPDF_Dictionary* pDict,
+                                         const CPDF_Dictionary* pDict,
                                          bool bDirect) {
   CPDF_ContentMarkItem item;
   item.SetName(name);
diff --git a/core/fpdfapi/page/cpdf_contentmark.h b/core/fpdfapi/page/cpdf_contentmark.h
index 78a948697e..1d8b9e2515 100644
--- a/core/fpdfapi/page/cpdf_contentmark.h
+++ b/core/fpdfapi/page/cpdf_contentmark.h
@@ -25,7 +25,9 @@ class CPDF_ContentMark {
   size_t CountItems() const;
   const CPDF_ContentMarkItem& GetItem(size_t i) const;
 
-  void AddMark(const ByteString& name, CPDF_Dictionary* pDict, bool bDirect);
+  void AddMark(const ByteString& name,
+               const CPDF_Dictionary* pDict,
+               bool bDirect);
   void DeleteLastMark();
 
   bool HasRef() const { return !!m_Ref; }
@@ -42,7 +44,7 @@ class CPDF_ContentMark {
 
     int GetMarkedContentID() const;
     void AddMark(const ByteString& name,
-                 CPDF_Dictionary* pDict,
+                 const CPDF_Dictionary* pDict,
                  bool bDictNeedClone);
     void DeleteLastMark();
 
diff --git a/core/fpdfapi/page/cpdf_contentmarkitem.cpp b/core/fpdfapi/page/cpdf_contentmarkitem.cpp
index de720b39fc..205f14de35 100644
--- a/core/fpdfapi/page/cpdf_contentmarkitem.cpp
+++ b/core/fpdfapi/page/cpdf_contentmarkitem.cpp
@@ -10,8 +10,7 @@
 
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
 
-CPDF_ContentMarkItem::CPDF_ContentMarkItem()
-    : m_ParamType(None), m_pPropertiesDict(nullptr) {}
+CPDF_ContentMarkItem::CPDF_ContentMarkItem() {}
 
 CPDF_ContentMarkItem::CPDF_ContentMarkItem(const CPDF_ContentMarkItem& that)
     : m_MarkName(that.m_MarkName),
@@ -23,7 +22,7 @@ CPDF_ContentMarkItem::CPDF_ContentMarkItem(const CPDF_ContentMarkItem& that)
 
 CPDF_ContentMarkItem::~CPDF_ContentMarkItem() {}
 
-CPDF_Dictionary* CPDF_ContentMarkItem::GetParam() const {
+const CPDF_Dictionary* CPDF_ContentMarkItem::GetParam() const {
   switch (m_ParamType) {
     case PropertiesDict:
       return m_pPropertiesDict.Get();
@@ -36,7 +35,7 @@ CPDF_Dictionary* CPDF_ContentMarkItem::GetParam() const {
 }
 
 bool CPDF_ContentMarkItem::HasMCID() const {
-  CPDF_Dictionary* pDict = GetParam();
+  const CPDF_Dictionary* pDict = GetParam();
   return pDict && pDict->KeyExist("MCID");
 }
 
@@ -46,7 +45,7 @@ void CPDF_ContentMarkItem::SetDirectDict(
   m_pDirectDict = std::move(pDict);
 }
 
-void CPDF_ContentMarkItem::SetPropertiesDict(CPDF_Dictionary* pDict) {
+void CPDF_ContentMarkItem::SetPropertiesDict(const CPDF_Dictionary* pDict) {
   m_ParamType = PropertiesDict;
   m_pPropertiesDict = pDict;
 }
diff --git a/core/fpdfapi/page/cpdf_contentmarkitem.h b/core/fpdfapi/page/cpdf_contentmarkitem.h
index ea89606816..5dcc7d480a 100644
--- a/core/fpdfapi/page/cpdf_contentmarkitem.h
+++ b/core/fpdfapi/page/cpdf_contentmarkitem.h
@@ -28,18 +28,18 @@ class CPDF_ContentMarkItem {
 
   ByteString GetName() const { return m_MarkName; }
   ParamType GetParamType() const { return m_ParamType; }
-  CPDF_Dictionary* GetParam() const;
+  const CPDF_Dictionary* GetParam() const;
   bool HasMCID() const;
 
   void SetName(const ByteString& name) { m_MarkName = name; }
   void SetDirectDict(std::unique_ptr<CPDF_Dictionary> pDict);
-  void SetPropertiesDict(CPDF_Dictionary* pDict);
+  void SetPropertiesDict(const CPDF_Dictionary* pDict);
 
  private:
   ByteString m_MarkName;
-  ParamType m_ParamType;
-  UnownedPtr<CPDF_Dictionary> m_pPropertiesDict;
-  std::unique_ptr<CPDF_Dictionary> m_pDirectDict;
+  ParamType m_ParamType = None;
+  UnownedPtr<const CPDF_Dictionary> m_pPropertiesDict;
+  std::unique_ptr<const CPDF_Dictionary> m_pDirectDict;
 };
 
 #endif  // CORE_FPDFAPI_PAGE_CPDF_CONTENTMARKITEM_H_
diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.cpp b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
index 4e3857bf85..697349e987 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
@@ -586,10 +586,10 @@ void CPDF_StreamContentParser::Handle_EOFillStrokePath() {
 
 void CPDF_StreamContentParser::Handle_BeginMarkedContent_Dictionary() {
   ByteString tag = GetString(1);
-  CPDF_Object* pProperty = GetObject(0);
-  if (!pProperty) {
+  const CPDF_Object* pProperty = GetObject(0);
+  if (!pProperty)
     return;
-  }
+
   bool bDirect = true;
   if (pProperty->IsName()) {
     pProperty = FindResourceObj("Properties", pProperty->GetString());
@@ -597,7 +597,7 @@ void CPDF_StreamContentParser::Handle_BeginMarkedContent_Dictionary() {
       return;
     bDirect = false;
   }
-  if (CPDF_Dictionary* pDict = pProperty->AsDictionary()) {
+  if (const CPDF_Dictionary* pDict = pProperty->AsDictionary()) {
     m_CurContentMark.AddMark(tag, pDict, bDirect);
   }
 }