Use const pointers within GetDirectInteger function.

Change-Id: I4a2905f9ce4433e8c00b274fa9703ff4dc459e95
Reviewed-on: https://pdfium-review.googlesource.com/35510
Commit-Queue: Art Snake <art-snake@yandex-team.ru>
Reviewed-by: dsinclair <dsinclair@chromium.org>
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.cpp b/core/fpdfapi/parser/fpdf_parser_utility.cpp
index 1dad2a8..3c99415 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.cpp
+++ b/core/fpdfapi/parser/fpdf_parser_utility.cpp
@@ -84,8 +84,8 @@
   return kInvalidHeaderOffset;
 }
 
-int32_t GetDirectInteger(CPDF_Dictionary* pDict, const ByteString& key) {
-  CPDF_Number* pObj = ToNumber(pDict->GetObjectFor(key));
+int32_t GetDirectInteger(const CPDF_Dictionary* pDict, const ByteString& key) {
+  const CPDF_Number* pObj = ToNumber(pDict->GetObjectFor(key));
   return pObj ? pObj->GetInteger() : 0;
 }
 
diff --git a/core/fpdfapi/parser/fpdf_parser_utility.h b/core/fpdfapi/parser/fpdf_parser_utility.h
index 3ae8f6f..7529fbc 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.h
+++ b/core/fpdfapi/parser/fpdf_parser_utility.h
@@ -43,7 +43,7 @@
 // |kInvalidHeaderOffset|.
 int32_t GetHeaderOffset(const RetainPtr<IFX_SeekableReadStream>& pFile);
 
-int32_t GetDirectInteger(CPDF_Dictionary* pDict, const ByteString& key);
+int32_t GetDirectInteger(const CPDF_Dictionary* pDict, const ByteString& key);
 
 ByteString PDF_NameDecode(const ByteStringView& orig);
 ByteString PDF_NameEncode(const ByteString& orig);