Fix infinite recursion in CPDF_DocPageData::GetColorSpace().

core/fpdfapi/fpdf_page/pageint.h

Index: core/fpdfapi/fpdf_page/pageint.h
diff --git a/core/fpdfapi/fpdf_page/pageint.h b/core/fpdfapi/fpdf_page/pageint.h
index 64d106f1dc46e6245b62943bf9504ce593c4b6da..b884338f7658b34079f79e10526b8b7799455237 100644
--- a/core/fpdfapi/fpdf_page/pageint.h
+++ b/core/fpdfapi/fpdf_page/pageint.h
@@ -10,6 +10,7 @@
 #include <map>
 #include <memory>
 #include <unordered_map>
+#include <set>
 #include <vector>
 
 #include "core/fpdfapi/fpdf_page/cpdf_contentmark.h"
@@ -356,6 +357,10 @@ class CPDF_DocPageData {
   using CPDF_ImageMap = std::map<uint32_t, CPDF_CountedImage*>;
   using CPDF_PatternMap = std::map<CPDF_Object*, CPDF_CountedPattern*>;
 
+  CPDF_ColorSpace* GetColorSpaceImpl(CPDF_Object* pCSObj,
+                                     const CPDF_Dictionary* pResources,
+                                     std::set<CPDF_Object*>* pVisited);
+
   CPDF_Document* const m_pPDFDoc;
   FX_BOOL m_bForceClear;
   std::map<CFX_ByteString, CPDF_Stream*> m_HashProfileMap;