Change GetHeaderOffset() to return Optional<FX_FILESIZE>.

Remove |kInvalidHeaderOffset|.

Change-Id: I5978e745e97aa4e13299dd21028721725ac0c996
Reviewed-on: https://pdfium-review.googlesource.com/38853
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Art Snake <art-snake@yandex-team.ru>

1 files changed, 6 insertions, 6 deletions

diff --git a/core/fpdfapi/parser/fpdf_parser_utility.h b/core/fpdfapi/parser/fpdf_parser_utility.h
index 7529fbc484..5fe9b5d4a9 100644
--- a/core/fpdfapi/parser/fpdf_parser_utility.h
+++ b/core/fpdfapi/parser/fpdf_parser_utility.h
@@ -11,10 +11,11 @@
 
 #include "core/fxcrt/fx_string.h"
 #include "core/fxcrt/retain_ptr.h"
+#include "third_party/base/optional.h"
 
-class IFX_SeekableReadStream;
 class CPDF_Dictionary;
 class CPDF_Object;
+class IFX_SeekableReadStream;
 
 // Use the accessors below instead of directly accessing PDF_CharType.
 extern const char PDF_CharType[256];
@@ -36,12 +37,11 @@ inline bool PDFCharIsLineEnding(uint8_t c) {
   return c == '\r' || c == '\n';
 }
 
-constexpr int32_t kInvalidHeaderOffset = -1;
-
-// On success, return a positive offset value to the PDF header.. If the header
+// On success, return a positive offset value to the PDF header. If the header
 // cannot be found, or if there is an error reading from |pFile|, then return
-// |kInvalidHeaderOffset|.
-int32_t GetHeaderOffset(const RetainPtr<IFX_SeekableReadStream>& pFile);
+// nullopt.
+Optional<FX_FILESIZE> GetHeaderOffset(
+    const RetainPtr<IFX_SeekableReadStream>& pFile);
 
 int32_t GetDirectInteger(const CPDF_Dictionary* pDict, const ByteString& key);