Add some more consts to unowned pointers.

Ideally, unowned ptrs might well be const, as updating something
through an unowned reference is best avoided.

Change-Id: Ida8111ffe0ee1e30bbf6b7718b0929dfb5cafdff
Reviewed-on: https://pdfium-review.googlesource.com/36050
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

6 files changed, 14 insertions, 15 deletions

diff --git a/core/fpdfapi/page/cpdf_generalstate.cpp b/core/fpdfapi/page/cpdf_generalstate.cpp
index a5b718bfff..2657578ab7 100644
--- a/core/fpdfapi/page/cpdf_generalstate.cpp
+++ b/core/fpdfapi/page/cpdf_generalstate.cpp
@@ -154,7 +154,7 @@ void CPDF_GeneralState::SetSoftMask(CPDF_Object* pObject) {
   m_Ref.GetPrivateCopy()->m_pSoftMask = pObject;
 }
 
-CPDF_Object* CPDF_GeneralState::GetTR() const {
+const CPDF_Object* CPDF_GeneralState::GetTR() const {
   const StateData* pData = m_Ref.GetObject();
   return pData ? pData->m_pTR.Get() : nullptr;
 }
@@ -262,7 +262,6 @@ CFX_Matrix* CPDF_GeneralState::GetMutableMatrix() {
 CPDF_GeneralState::StateData::StateData()
     : m_BlendMode(pdfium::transparency::kNormal),
       m_BlendType(0),
-      m_pSoftMask(nullptr),
       m_StrokeAlpha(1.0),
       m_FillAlpha(1.0f),
       m_pTR(nullptr),
diff --git a/core/fpdfapi/page/cpdf_generalstate.h b/core/fpdfapi/page/cpdf_generalstate.h
index 5d6d5dc552..4a101b99de 100644
--- a/core/fpdfapi/page/cpdf_generalstate.h
+++ b/core/fpdfapi/page/cpdf_generalstate.h
@@ -40,7 +40,7 @@ class CPDF_GeneralState {
   CPDF_Object* GetSoftMask() const;
   void SetSoftMask(CPDF_Object* pObject);
 
-  CPDF_Object* GetTR() const;
+  const CPDF_Object* GetTR() const;
   void SetTR(CPDF_Object* pObject);
 
   RetainPtr<CPDF_TransferFunc> GetTransferFunc() const;
@@ -89,7 +89,7 @@ class CPDF_GeneralState {
     CFX_Matrix m_SMaskMatrix;
     float m_StrokeAlpha;
     float m_FillAlpha;
-    UnownedPtr<CPDF_Object> m_pTR;
+    UnownedPtr<const CPDF_Object> m_pTR;
     RetainPtr<CPDF_TransferFunc> m_pTransferFunc;
     CFX_Matrix m_Matrix;
     int m_RenderIntent;
@@ -99,9 +99,9 @@ class CPDF_GeneralState {
     bool m_StrokeOP;
     bool m_FillOP;
     int m_OPMode;
-    UnownedPtr<CPDF_Object> m_pBG;
-    UnownedPtr<CPDF_Object> m_pUCR;
-    UnownedPtr<CPDF_Object> m_pHT;
+    UnownedPtr<const CPDF_Object> m_pBG;
+    UnownedPtr<const CPDF_Object> m_pUCR;
+    UnownedPtr<const CPDF_Object> m_pHT;
     float m_Flatness;
     float m_Smoothness;
   };
diff --git a/core/fpdfapi/page/cpdf_image.h b/core/fpdfapi/page/cpdf_image.h
index 9281a2c77d..be5883b946 100644
--- a/core/fpdfapi/page/cpdf_image.h
+++ b/core/fpdfapi/page/cpdf_image.h
@@ -29,9 +29,9 @@ class CPDF_Image : public Retainable {
 
   void ConvertStreamToIndirectObject();
 
-  CPDF_Stream* GetStream() const { return m_pStream.Get(); }
   CPDF_Dictionary* GetDict() const;
-  CPDF_Dictionary* GetOC() const { return m_pOC.Get(); }
+  CPDF_Stream* GetStream() const { return m_pStream.Get(); }
+  const CPDF_Dictionary* GetOC() const { return m_pOC.Get(); }
   CPDF_Document* GetDocument() const { return m_pDocument.Get(); }
 
   int32_t GetPixelHeight() const { return m_Height; }
@@ -82,7 +82,7 @@ class CPDF_Image : public Retainable {
   bool m_bInterpolate = false;
   UnownedPtr<CPDF_Document> const m_pDocument;
   MaybeOwned<CPDF_Stream> m_pStream;
-  UnownedPtr<CPDF_Dictionary> m_pOC;
+  UnownedPtr<const CPDF_Dictionary> m_pOC;
 };
 
 #endif  // CORE_FPDFAPI_PAGE_CPDF_IMAGE_H_
diff --git a/core/fpdfapi/page/cpdf_shadingobject.h b/core/fpdfapi/page/cpdf_shadingobject.h
index 69b606749d..af88128443 100644
--- a/core/fpdfapi/page/cpdf_shadingobject.h
+++ b/core/fpdfapi/page/cpdf_shadingobject.h
@@ -33,7 +33,7 @@ class CPDF_ShadingObject : public CPDF_PageObject {
   const CFX_Matrix& matrix() const { return m_Matrix; }
 
  private:
-  UnownedPtr<CPDF_ShadingPattern> m_pShading;
+  UnownedPtr<const CPDF_ShadingPattern> m_pShading;
   CFX_Matrix m_Matrix;
 };
 
diff --git a/core/fpdfapi/page/cpdf_shadingpattern.h b/core/fpdfapi/page/cpdf_shadingpattern.h
index 3c68c818ea..d7aa1cb272 100644
--- a/core/fpdfapi/page/cpdf_shadingpattern.h
+++ b/core/fpdfapi/page/cpdf_shadingpattern.h
@@ -55,7 +55,7 @@ class CPDF_ShadingPattern : public CPDF_Pattern {
   ShadingType GetShadingType() const { return m_ShadingType; }
   bool IsShadingObject() const { return m_bShadingObj; }
   const CPDF_Object* GetShadingObject() const { return m_pShadingObj.Get(); }
-  CPDF_ColorSpace* GetCS() const { return m_pCS.Get(); }
+  const CPDF_ColorSpace* GetCS() const { return m_pCS.Get(); }
   const std::vector<std::unique_ptr<CPDF_Function>>& GetFuncs() const {
     return m_pFunctions;
   }
@@ -73,9 +73,9 @@ class CPDF_ShadingPattern : public CPDF_Pattern {
 
   // Still keep |m_pCS| as some CPDF_ColorSpace (name object) are not managed
   // as counted objects. Refer to CPDF_DocPageData::GetColorSpace.
-  UnownedPtr<CPDF_ColorSpace> m_pCS;
+  UnownedPtr<const CPDF_ColorSpace> m_pCS;
 
-  UnownedPtr<CPDF_CountedColorSpace> m_pCountedCS;
+  UnownedPtr<const CPDF_CountedColorSpace> m_pCountedCS;
   std::vector<std::unique_ptr<CPDF_Function>> m_pFunctions;
 };
 
diff --git a/core/fpdfapi/page/cpdf_streamcontentparser.cpp b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
index 9d6e86def0..8f3e70a278 100644
--- a/core/fpdfapi/page/cpdf_streamcontentparser.cpp
+++ b/core/fpdfapi/page/cpdf_streamcontentparser.cpp
@@ -76,7 +76,7 @@ CFX_FloatRect GetShadingBBox(CPDF_ShadingPattern* pShading,
                              const CFX_Matrix& matrix) {
   ShadingType type = pShading->GetShadingType();
   const CPDF_Stream* pStream = ToStream(pShading->GetShadingObject());
-  CPDF_ColorSpace* pCS = pShading->GetCS();
+  const CPDF_ColorSpace* pCS = pShading->GetCS();
   if (!pStream || !pCS)
     return CFX_FloatRect();